String matching

String matching
You are encouraged to solve this task according to the task description, using any language you may know.

Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.

You may see other such operations in the Basic Data Operations category, or:

Integer Operations
Arithmetic | Comparison

Boolean Operations
Bitwise | Logical

String Operations
Concatenation | Interpolation | Comparison | Matching

Memory Operations

Given two strings, demonstrate the following three types of string matching:

1.   Determining if the first string starts with second string
2.   Determining if the first string contains the second string at any location
3.   Determining if the first string ends with the second string

Optional requirements:

1.   Print the location of the match for part 2
2.   Handle multiple occurrences of a string for part 2.

11l

Translation of: Python

<lang 11l>print(‘abcd’.starts_with(‘ab’)) print(‘abcd’.ends_with(‘zn’)) print(‘bb’ C ‘abab’) print(‘ab’ C ‘abab’) print(‘abab’.find(‘bb’) ? -1) print(‘abab’.find(‘ab’) ? -1)</lang>

Output:
```1B
0B
0B
1B
-1
0
```

360 Assembly

<lang 360asm>* String matching 04/04/2017 STRMATCH CSECT

```        USING  STRMATCH,R15
XPRNT  SS,L'SS
```
```        CLC    SS(L'S1),S1
BNE    NOT1
XPRNT  =C'-- STARTS WITH',14
XPRNT  S1,L'S1
```

NOT1 EQU *

```        CLC    SS+L'SS-L'S2(L'S2),S2
BNE    NOT2
XPRNT  =C'-- ENDS WITH',12
XPRNT  S2,L'S2
```

NOT2 EQU *

```        LA     R0,L'SS-L'S3+1
LA     R1,SS
```

LOOP CLC 0(L'S3,R1),S3

```        BNE    NOT3
XPRNT  =C'-- CONTAINS',11
XPRNT  S3,L'S3
```

NOT3 LA R1,1(R1)

```        BCT    R0,LOOP
```
```        BR     R14
```

SS DC CL6'ABCDEF' S1 DC CL2'AB' S2 DC CL2'EF' S3 DC CL2'CD' PG DC CL80' '

```        YREGS
END    STRMATCH</lang>
```
Output:
```ABCDEF
-- STARTS WITH
AB
-- ENDS WITH
EF
-- CONTAINS
CD
```

AArch64 Assembly

Works with: as version Raspberry Pi 3B version Buster 64 bits

<lang AArch64 Assembly> /* ARM assembly AARCH64 Raspberry PI 3B */ /* program strMatching64.s */

/*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc" /*******************************************/ /* Initialized data */ /*******************************************/ .data szMessFound: .asciz "String found. \n" szMessNotFound: .asciz "String not found. \n" szString: .asciz "abcdefghijklmnopqrstuvwxyz" szString2: .asciz "abc" szStringStart: .asciz "abcd" szStringEnd: .asciz "xyz" szStringStart2: .asciz "abcd" szStringEnd2: .asciz "xabc" szCarriageReturn: .asciz "\n" /*******************************************/ /* UnInitialized data */ /*******************************************/ .bss /*******************************************/ /* code section */ /*******************************************/ .text .global main main:

```   ldr x0,qAdrszString                  // address input string

bl searchStringDeb                   // Determining if the first string starts with second string
cmp x0,0
ble 1f
bl affichageMess
b 2f
```

1:

```   ldr x0,qAdrszMessNotFound
bl affichageMess
```

2:

```   ldr x0,qAdrszString                 // address input string
bl searchStringFin                  // Determining if the first string ends with the second string
cmp x0,0
ble 3f
bl affichageMess
b 4f
```

3:

```   ldr x0,qAdrszMessNotFound
bl affichageMess
```

4:

```   ldr x0,qAdrszString2               // address input string

bl searchStringDeb                 //
cmp x0,0
ble 5f
bl affichageMess
b 6f
```

5:

```   ldr x0,qAdrszMessNotFound
bl affichageMess
```

6:

```   ldr x0,qAdrszString2               // address input string
bl searchStringFin
cmp x0,0
ble 7f
bl affichageMess
b 8f
```

7:

```   ldr x0,qAdrszMessNotFound
bl affichageMess
```

8:

```   ldr x0,qAdrszString               // address input string
bl searchSubString                // Determining if the first string contains the second string at any location
cmp x0,0
ble 9f
bl affichageMess
b 10f
```

9:

```   ldr x0,qAdrszMessNotFound         // display substring result
bl affichageMess
```

10:

100: // standard end of the program

```   mov x0,0                          // return code
mov x8,EXIT                       // request to exit program
svc 0                             // perform system call
```

```   stp x1,lr,[sp,-16]!            // save  registers
stp x2,x3,[sp,-16]!            // save  registers
mov x3,0                       // counter byte  string
ldrb w4,[x1,x3]                // load first byte of substring
cbz x4,99f                     // empty string ?
```

1:

```   ldrb w2,[x0,x3]                // load byte string input
cbz x2,98f                     // zero final ?
cmp x4,x2                      // bytes equals ?
bne 98f                        // no not find
ldrb w4,[x1,x3]                // and load next byte of substring
cbnz x4,1b                     // zero final ?
mov x0,1                       // yes is ok
b 100f
```

98:

```   mov x0,0                       // not find
b 100f
```

99:

```   mov x0,-1                      // error
```

100:

```   ldp x2,x3,[sp],16              // restaur  2 registers
ldp x1,lr,[sp],16              // restaur  2 registers

```

/******************************************************************/ /* search substring at end of input string */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of substring */ /* x0 returns 1 if find or 0 if not or -1 if error */ searchStringFin:

```   stp x1,lr,[sp,-16]!            // save  registers
stp x2,x3,[sp,-16]!            // save  registers
stp x4,x5,[sp,-16]!            // save  registers
mov x3,0                       // counter byte  string
// search the last character of substring
```

1:

```   ldrb w4,[x1,x3]                // load byte of substring
cmp x4,#0                      // zero final ?
csel x3,x2,x3,ne               // no increment counter
//addne x3,#1                  // no increment counter
bne 1b                         // and loop
cbz x3,99f                     // empty string ?
```
```   sub x3,x3,1                    // index of last byte
ldrb w4,[x1,x3]                // load last byte of substring
// search the last character of string
mov x2,0                       // index last character
```

2:

```   ldrb w5,[x0,x2]                // load first byte of substring
cmp x5,0                       // zero final ?
add x5,x2,1                    // no -> increment counter
csel x2,x5,x2,ne
//addne x2,#1                  // no -> increment counter
bne 2b                         // and loop
cbz x2,98f                     // empty input string ?
sub x2,x2,1                    // index last character
```

3:

```   ldrb w5,[x0,x2]                // load byte string input
cmp x4,x5                      // bytes equals ?
subs x3,x3,1                   // decrement counter
blt 97f                        //  ok found
subs x2,x2,1                   // decrement counter input string
ldrb w4,[x1,x3]                // load previous byte of substring
b 3b                           // and loop
```

97:

```   mov x0,1                       // yes is ok
b 100f
```

98:

```   mov x0,0                       // not found
b 100f
```

99:

```   mov x0,-1                      // error
```

100:

```   ldp x4,x5,[sp],16              // restaur  2 registers
ldp x2,x3,[sp],16              // restaur  2 registers
ldp x1,lr,[sp],16              // restaur  2 registers

```

/******************************************************************/ /* search a substring in the string */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of substring */ /* x0 returns index of substring in string or -1 if not found */ searchSubString:

```   stp x1,lr,[sp,-16]!            // save  registers
stp x2,x3,[sp,-16]!            // save  registers
stp x4,x5,[sp,-16]!            // save  registers
mov x2,0                       // counter byte input string
mov x3,0                       // counter byte string
mov x6,-1                      // index found
ldrb w4,[x1,x3]
```

1:

```   ldrb w5,[x0,x2]                // load byte string
cbz x5,99f                     // zero final ?
cmp x5,x4                      // compare character
beq 2f
mov x6,-1                      // no equals - > raz index
mov x3,0                       // and raz counter byte
add x2,x2,1                    // and increment counter byte
b 1b                           // and loop
```

2: // characters equals

```   cmp x6,-1                      // first characters equals ?
csel x6,x2,x6,eq               // yes -> index begin in x6
//moveq x6,x2                  // yes -> index begin in x6
add x3,x3,1                    // increment counter substring
ldrb w4,[x1,x3]                // and load next byte
cmp x4,0                       // zero final ?
beq 3f                         // yes -> end search
add x2,x2,1                    // else increment counter string
b 1b                           // and loop
```

3:

```   mov x0,x6
b 100f
```

98:

```   mov x0,0                      // not found
b 100f
```

99:

```   mov x0,-1                     // error
```

100:

```   ldp x4,x5,[sp],16              // restaur  2 registers
ldp x2,x3,[sp],16              // restaur  2 registers
ldp x1,lr,[sp],16              // restaur  2 registers
```

/********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc" </lang>

Action!

<lang Action!>BYTE FUNC FindS(CHAR ARRAY text,sub BYTE start)

``` BYTE i,j,found
```
``` i=start
WHILE i<=text(0)-sub(0)+1
DO
found=0
FOR j=1 TO sub(0)
DO
IF text(i+j-1)#sub(j) THEN
found=0 EXIT
ELSE
found=1
FI
OD
IF found THEN
RETURN (i)
FI
i==+1
OD
```

RETURN (0)

BYTE FUNC StartsWith(CHAR ARRAY text,sub)

``` BYTE pos
```
``` pos=FindS(text,sub,1)
IF pos=1 THEN
RETURN (1)
FI
```

RETURN (0)

BYTE FUNC EndsWith(CHAR ARRAY text,sub)

``` BYTE pos,start
```
``` IF sub(0)>text(0) THEN
RETURN (0)
FI
start=text(0)-sub(0)+1
pos=FindS(text,sub,start)
IF pos=start THEN
RETURN (1)
FI
```

RETURN (0)

BYTE FUNC Contains(CHAR ARRAY text,sub

```                 BYTE ARRAY positions)
BYTE pos,count
```
``` pos=1 count=0
WHILE pos<=text(0)
DO
pos=FindS(text,sub,pos)
IF pos>0 THEN
positions(count)=pos
count==+1
pos==+1
ELSE
EXIT
FI
OD
```

RETURN (count)

PROC TestStartsWith(CHAR ARRAY text,sub)

``` IF StartsWith(text,sub) THEN
PrintF("""%S"" starts with ""%S"".%E",text,sub)
ELSE
FI
```

RETURN

PROC TestEndsWith(CHAR ARRAY text,sub)

``` IF EndsWith(text,sub) THEN
PrintF("""%S"" ends with ""%S"".%E",text,sub)
ELSE
PrintF("""%S"" does not end with ""%S"".%E",text,sub)
FI
```

RETURN

PROC TestContains(CHAR ARRAY text,sub)

``` BYTE ARRAY positions(20)
BYTE i,count
```
``` count=Contains(text,sub,positions)
IF count>0 THEN
PrintF("""%S"" contains %B ""%S"" at positions:",text,count,sub)
FOR i=0 TO count-1
DO
PrintB(positions(i))
IF i<count-1 THEN
Print(", ")
ELSE
PrintE(".")
FI
OD
ELSE
PrintF("""%S"" does not contain ""%S"".%E",text,sub)
FI
```

RETURN

PROC Main()

``` TestStartsWith("1234abc","123")
TestStartsWith("1234abc","234")
PutE()
TestContains("abbaabab","ab")
TestContains("abbaabab","ba")
TestContains("abbaabab","xyz")
PutE()
TestEndsWith("1234abc","abc")
TestEndsWith("1234abc","ab")
```

RETURN</lang>

Output:
```"1234abc" starts with "123".

"abbaabab" contains 3 "ab" at positions:1, 5, 7.
"abbaabab" contains 2 "ba" at positions:3, 6.
"abbaabab" does not contain "xyz".

"1234abc" ends with "abc".
"1234abc" does not end with "ab".
```

procedure Match_Strings is

```  S1 : constant String := "abcd";
S2 : constant String := "abab";
S3 : constant String := "ab";
```

begin

```  if S1'Length >= S3'Length and then S1 (S1'First..S1'First + S3'Length - 1) = S3 then
Put_Line ( & S1 & "' starts with '" & S3 & );
end if;
if S2'Length >= S3'Length and then S2 (S2'Last - S3'Length + 1..S2'Last) = S3 then
Put_Line ( & S2 & "' ends with '" & S3 & );
end if;
Put_Line ( & S3 & "' first appears in '" & S1 & "' at" & Integer'Image (Index (S1, S3)));
Put_Line
(   & S3 & "' appears in '" & S2 &  &
Integer'Image (Ada.Strings.Fixed.Count (S2, S3)) & " times"
);
```

end Match_Strings; </lang>

Output:
```'abcd' starts with 'ab'
'abab' ends with 'ab'
'ab' first appears in 'abcd' at 1
'ab' appears in 'abab' 2 times
```

Aime

<lang aime>text t; data b;

b = "Bangkok";

t = "Bang";

o_form("starts with, embeds, ends with \"~\": ~, ~, ~\n", t, b.seek(t) == 0,

```      b.seek(t) != -1,
b.seek(t) != -1 && b.seek(t) + ~t == ~b);
```

t = "ok";

o_form("starts with, embeds, ends with \"~\": ~, ~, ~\n", t, b.seek(t) == 0,

```      b.seek(t) != -1,
b.seek(t) != -1 && b.seek(t) + ~t == ~b);
```

t = "Summer";

o_form("starts with, embeds, ends with \"~\": ~, ~, ~\n", t, b.seek(t) == 0,

```      b.seek(t) != -1,
b.seek(t) != -1 && b.seek(t) + ~t == ~b);</lang>
```
Output:
```starts with, embeds, ends with "Bang": 1, 1, 0
starts with, embeds, ends with "ok": 0, 1, 1
starts with, embeds, ends with "Summer": 0, 0, 0```

ALGOL 68

Translation of: python
Works with: ALGOL 68 version Revision 1 - no extensions to language used
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny

<lang algol68># define some appropriate OPerators # PRIO STARTSWITH = 5, ENDSWITH = 5; OP STARTSWITH = (STRING str, prefix)BOOL: # assuming LWB = 1 #

``` IF UPB str < UPB prefix THEN FALSE ELSE str[:UPB prefix]=prefix FI;
```

OP ENDSWITH = (STRING str, suffix)BOOL: # assuming LWB = 1 #

``` IF UPB str < UPB suffix THEN FALSE ELSE str[UPB str-UPB suffix+1:]=suffix FI;
```

INT loc, loc2;

print((

``` "abcd" STARTSWITH "ab", # returns TRUE #
"abcd" ENDSWITH "zn", # returns FALSE #
string in string("bb",loc,"abab"), # returns FALSE #
string in string("ab",loc,"abab"), # returns TRUE #
(string in string("bb",loc,"abab")|loc|-1), # returns -1 #
(string in string("ab",loc,"abab")|loc|-1), # returns +1 #
(string in string("ab",loc2,"abab"[loc+1:])|loc+loc2|-1) # returns +3 #
```

))</lang>

Output:
```TFFT         -1         +1         +3
```

AppleScript

<lang AppleScript>set stringA to "I felt happy because I saw the others were happy and because I knew I should feel happy, but I wasn’t really happy."

set string1 to "I felt happy" set string2 to "I should feel happy" set string3 to "I wasn't really happy"

-- Determining if the first string starts with second string stringA starts with string1 --> true

-- Determining if the first string contains the second string at any location stringA contains string2 --> true

-- Determining if the first string ends with the second string stringA ends with string3 --> false

-- Print the location of the match for part 2 offset of string2 in stringA --> 69</lang> AppleScript doesn't have a builtin means of matching multiple occurrences of a substring, however one can redefine the existing offset command to add this functionality: <lang AppleScript>-- Handle multiple occurrences of a string for part 2 on offset of needle in haystack local needle, haystack

if the needle is not in the haystack then return {} set my text item delimiters to the needle script property N : needle's length property t : {1 - N} & haystack's text items end script

tell the result repeat with i from 2 to (its t's length) - 1 set x to item i of its t set y to item (i - 1) of its t set item i of its t to (its N) + (x's length) + y end repeat

items 2 thru -2 of its t end tell end offset

offset of "happy" in stringA --> {8, 44, 83, 110}</lang>

or, defining an offsets function in terms of a more general findIndices: <lang applescript>-- offsets :: String -> String -> [Int] on offsets(needle, haystack)

```   script match
property mx : length of haystack
property d : (length of needle) - 1
on |λ|(x, i, xs)
set z to d + i
mx ≥ z and needle = text i thru z of xs
end |λ|
end script

findIndices(match, haystack)
```

end offsets

-- TEST --------------------------------------------------- on run

```   set txt to "I felt happy because I saw the others " & ¬
"were happy and because I knew I should " & ¬
"feel happy, but I wasn’t really happy."

offsets("happy", txt)

--> {8, 44, 83, 110}
```

end run

-- GENERIC -------------------------------------------------

-- concatMap :: (a -> [b]) -> [a] -> [b] on concatMap(f, xs)

```   set lng to length of xs
set acc to {}
tell mReturn(f)
repeat with i from 1 to lng
set acc to acc & (|λ|(item i of xs, i, xs))
end repeat
end tell
return acc
```

end concatMap

-- findIndices :: (a -> Bool) -> [a] -> [Int] -- findIndices :: (String -> Bool) -> String -> [Int] on findIndices(p, xs)

```   script go
property f : mReturn(p)
on |λ|(x, i, xs)
if f's |λ|(x, i, xs) then
{i}
else
{}
end if
end |λ|
end script
concatMap(go, xs)
```

end findIndices

-- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: First-class m => (a -> b) -> m (a -> b) on mReturn(f)

```   if script is class of f then
f
else
script
property |λ| : f
end script
end if
```

end mReturn</lang>

Output:
`{8, 44, 83, 110}`

ARM Assembly

Works with: as version Raspberry Pi

<lang ARM Assembly> /* ARM assembly Raspberry PI */ /* program strMatching.s */

/* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ WRITE, 4 @ Linux syscall

/* Initialized data */ .data szMessFound: .asciz "String found. \n" szMessNotFound: .asciz "String not found. \n" szString: .asciz "abcdefghijklmnopqrstuvwxyz" szString2: .asciz "abc" szStringStart: .asciz "abcd" szStringEnd: .asciz "xyz" szStringStart2: .asciz "abcd" szStringEnd2: .asciz "xabc" szCarriageReturn: .asciz "\n"

/* UnInitialized data */ .bss

/* code section */ .text .global main main:

```   ldr r0,iAdrszString                         @ address input string
```
```   bl searchStringDeb                          @ Determining if the first string starts with second string
cmp r0,#0
ble 1f
bl affichageMess
b 2f
```

1:

```   ldr r0,iAdrszMessNotFound
bl affichageMess
```

2:

```   ldr r0,iAdrszString                         @ address input string
bl searchStringFin                          @ Determining if the first string ends with the second string
cmp r0,#0
ble 3f
bl affichageMess
b 4f
```

3:

```   ldr r0,iAdrszMessNotFound
bl affichageMess
```

4:

```   ldr r0,iAdrszString2                        @ address input string
```
```   bl searchStringDeb                          @
cmp r0,#0
ble 5f
bl affichageMess
b 6f
```

5:

```   ldr r0,iAdrszMessNotFound
bl affichageMess
```

6:

```   ldr r0,iAdrszString2                        @ address input string
bl searchStringFin
cmp r0,#0
ble 7f
bl affichageMess
b 8f
```

7:

```   ldr r0,iAdrszMessNotFound
bl affichageMess
```

8:

```   ldr r0,iAdrszString                         @ address input string
bl searchSubString                          @ Determining if the first string contains the second string at any location
cmp r0,#0
ble 9f
bl affichageMess
b 10f
```

9:

```   ldr r0,iAdrszMessNotFound                   @ display substring result
bl affichageMess
```

10:

100: @ standard end of the program

```   mov r0, #0                                  @ return code
mov r7, #EXIT                               @ request to exit program
svc 0                                       @ perform system call
```

```   push {r1-r4,lr}                             @ save  registers
mov r3,#0                                   @ counter byte  string
ldrb r4,[r1,r3]                             @ load first byte of substring
cmp r4,#0                                   @ empty string ?
moveq r0,#-1                                @ error
beq 100f
```

1:

```   ldrb r2,[r0,r3]                             @ load byte string input
cmp r2,#0                                   @ zero final ?
moveq r0,#0                                 @ not find
beq 100f
cmp r4,r2                                   @ bytes equals ?
movne r0,#0                                 @ no not find
bne 100f
ldrb r4,[r1,r3]                             @ and load next byte of substring
cmp r4,#0                                   @ zero final ?
bne 1b                                      @ no -> loop
mov r0,#1                                   @ yes is ok
```

100:

```   pop {r1-r4,lr}                              @ restaur registers
bx lr                                       @ return
```

/******************************************************************/ /* search substring at end of input string */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of substring */ /* r0 returns 1 if find or 0 if not or -1 if error */ searchStringFin:

```   push {r1-r5,lr}                             @ save  registers
mov r3,#0                                   @ counter byte  string
@ search the last character of substring
```

1:

```   ldrb r4,[r1,r3]                             @ load byte of substring
cmp r4,#0                                   @ zero final ?
addne r3,#1                                 @ no increment counter
bne 1b                                      @ and loop
cmp r3,#0                                   @ empty string ?
moveq r0,#-1                                @ error
beq 100f
sub r3,#1                                   @ index of last byte
ldrb r4,[r1,r3]                             @ load last byte of substring
@ search the last character of string
mov r2,#0                                   @ index last character
```

2:

```   ldrb r5,[r0,r2]                             @ load first byte of substring
cmp r5,#0                                   @ zero final ?
addne r2,#1                                 @ no -> increment counter
bne 2b                                      @ and loop
cmp r2,#0                                   @ empty input string ?
beq 100f
sub r2,#1                                   @ index last character
```

3:

```   ldrb r5,[r0,r2]                             @ load byte string input
cmp r4,r5                                   @ bytes equals ?
bne 100f
subs r3,#1                                  @ decrement counter
movlt r0,#1                                 @ if zero -> ok found
blt 100f
subs r2,#1                                  @ decrement counter input string
blt 100f
ldrb r4,[r1,r3]                             @ load previous byte of substring
b 3b                                        @ and loop

```

100:

```   pop {r1-r5,lr}                              @ restaur registers
bx lr                                       @ return
```

/******************************************************************/ /* search a substring in the string */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of substring */ /* r0 returns index of substring in string or -1 if not found */ searchSubString:

```   push {r1-r6,lr}                       @ save registers
mov r2,#0                             @ counter byte input string
mov r3,#0                             @ counter byte string
mov r6,#-1                            @ index found
ldrb r4,[r1,r3]
```

1:

```   ldrb r5,[r0,r2]                       @ load byte string
cmp r5,#0                             @ zero final ?
moveq r0,#-1                          @ yes returns error
beq 100f
cmp r5,r4                             @ compare character
beq 2f
mov r6,#-1                            @ no equals - > raz index
mov r3,#0                             @ and raz counter byte
add r2,#1                             @ and increment counter byte
b 1b                                  @ and loop
```

2: @ characters equals

```   cmp r6,#-1                            @ first characters equals ?
moveq r6,r2                           @ yes -> index begin in r6
add r3,#1                             @ increment counter substring
ldrb r4,[r1,r3]                       @ and load next byte
cmp r4,#0                             @ zero final ?
beq 3f                                @ yes -> end search
add r2,#1                             @ else increment counter string
b 1b                                  @ and loop
```

3:

```   mov r0,r6
```

100:

```   pop {r1-r6,lr}                        @ restaur registers
bx lr
```

/******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess:

```   push {r0,r1,r2,r7,lr}                       @ save  registers
mov r2,#0                                   @ counter length */
```

1: @ loop length calculation

```   ldrb r1,[r0,r2]                             @ read octet start position + index
cmp r1,#0                                   @ if 0 its over
bne 1b                                      @ and loop
@ so here r2 contains the length of the message
mov r1,r0                                   @ address message in r1
mov r0,#STDOUT                              @ code to write to the standard output Linux
mov r7, #WRITE                              @ code call system "write"
svc #0                                      @ call system
pop {r0,r1,r2,r7,lr}                        @ restaur registers
bx lr                                       @ return
```

</lang>

Arturo

<lang rebol>print prefix? "abcd" "ab" print prefix? "abcd" "cd" print suffix? "abcd" "ab" print suffix? "abcd" "cd"

print contains? "abcd" "ab" print contains? "abcd" "xy"

print in? "ab" "abcd" print in? "xy" "abcd"

print index "abcd" "bc" print index "abcd" "xy"</lang>

Output:
```true
false
false
true
true
false
true
false
1
null```

AutoHotkey

<lang AutoHotkey> String1 = abcd String2 = abab

If (SubStr(String1,1,StrLen(String2)) = String2)

```MsgBox, "%String1%" starts with "%String2%".
```

IfInString, String1, %String2% {

```Position := InStr(String1,String2)
StringReplace, String1, String1, %String2%, %String2%, UseErrorLevel
MsgBox, "%String1%" contains "%String2%" at position %Position%`, and appears %ErrorLevel% times.
```

} StringRight, TempVar, String1, StrLen(String2) If TempVar = %String2%

```MsgBox, "%String1%" ends with "%String2%".
```

</lang>

AutoIt

<lang AutoIt>\$string1 = "arduinoardblobard" \$string2 = "ard"

== Determining if the first string starts with second string

If StringLeft(\$string1, StringLen(\$string2)) = \$string2 Then ConsoleWrite("1st string starts with 2nd string." & @CRLF) Else ConsoleWrite("1st string does'nt starts with 2nd string." & @CRLF) EndIf

== Determining if the first string contains the second string at any location
== Print the location of the match for part 2
== Handle multiple occurrences of a string for part 2

\$start = 1 \$count = 0 \$pos = StringInStr(\$string1, \$string2) While \$pos \$count += 1 ConsoleWrite("1st string contains 2nd string at position: " & \$pos & @CRLF) \$pos = StringInStr(\$string1, \$string2, 0, 1, \$start + \$pos + StringLen(\$string2)) WEnd If \$count = 0 Then ConsoleWrite("1st string does'nt contain 2nd string." & @CRLF)

== Determining if the first string ends with the second string

If StringRight(\$string1, StringLen(\$string2)) = \$string2 Then ConsoleWrite("1st string ends with 2nd string." & @CRLF) Else ConsoleWrite("1st string does'nt ends with 2nd string." & @CRLF) EndIf

</lang>

AWK

<lang AWK>#!/usr/bin/awk -f {

```   if (\$1 ~ "^"\$2) {
```

print \$1" begins with "\$2;

```   } else {
```

print \$1" does not begin with "\$2;

```   }
```
```   if (\$1 ~ \$2) {
```

print \$1" contains "\$2;

```   } else {
```

print \$1" does not contain "\$2;

```   }
```
```   if (\$1 ~ \$2"\$") {
```

print \$1" ends with "\$2;

```   } else {
```

print \$1" does not end with "\$2;

```   }
```

} </lang>

BASIC

Works with: QBasic

<lang qbasic>first\$ = "qwertyuiop"

'Determining if the first string starts with second string second\$ = "qwerty" IF LEFT\$(first\$, LEN(second\$)) = second\$ THEN

```   PRINT "'"; first\$; "' starts with '"; second\$; "'"
```

ELSE

```   PRINT "'"; first\$; "' does not start with '"; second\$; "'"
```

END IF

'Determining if the first string contains the second string at any location 'Print the location of the match for part 2 second\$ = "wert" x = INSTR(first\$, second\$) IF x THEN

```   PRINT "'"; first\$; "' contains '"; second\$; "' at position "; x
```

ELSE

```   PRINT "'"; first\$; "' does not contain '"; second\$; "'"
```

END IF

' Determining if the first string ends with the second string second\$ = "random garbage" IF RIGHT\$(first\$, LEN(second\$)) = second\$ THEN

```   PRINT "'"; first\$; "' ends with '"; second\$; "'"
```

ELSE

```   PRINT "'"; first\$; "' does not end with '"; second\$; "'"
```

END IF

</lang>

Output:
```'qwertyuiop' starts with 'qwerty'
'qwertyuiop' contains 'wert' at position  2
'qwertyuiop' does not end with 'random garbage'
```

Applesoft BASIC

<lang ApplesoftBasic>10 A\$ = "THIS, THAT, AND THE OTHER THING" 20 S\$ = "TH" 30 DEF FN S(P) = MID\$(A\$, P, LEN(S\$)) = S\$ 40 PRINT A\$ : PRINT

110 S\$(1) = "STARTS" 120 S\$(0) = "DOES NOT START" 130 PRINT S\$(FN S(1))" WITH "S\$ : PRINT

210 R\$ = "" : FOR I = 1 TO LEN(A\$) - LEN(S\$) : IF FN S(I) THEN R\$ = R\$ + STR\$(I) + " " 220 NEXT I 230 IF LEN(R\$) = 0 THEN PRINT "DOES NOT CONTAIN "S\$ 240 IF LEN(R\$) THEN PRINT "CONTAINS "S\$" LOCATED AT POSITION "R\$ 250 PRINT

310 E\$(1) = "ENDS" 320 E\$(0) = "DOES NOT END" 330 PRINT E\$(FN S(LEN(A\$) - LEN(S\$) + 1))" WITH "S\$</lang>

Batch File

<lang dos>::NOTE #1: This implementation might crash, or might not work properly if

you put some of the CMD special characters (ex. %,!, etc) inside the strings.
NOTE #2: The comparisons here are case-SENSITIVE.
NOTE #3: Spaces in strings are considered.

@echo off setlocal enabledelayedexpansion

The main things...

set "str1=qwertyuiop" set "str2=qwerty" call :str2_lngth call :matchbegin

set "str1=qweiuoiocghiioyiocxiisfguiioiuygvd" set "str2=io" call :str2_lngth call :matchcontain

set "str1=blablabla" set "str2=bbla" call :str2_lngth call :matchend

echo. pause exit /b 0

/The main things.
The functions...
matchbegin

echo. if "!str1:~0,%length%!"=="!str2!" ( echo "%str1%" begins with "%str2%". ) else ( echo "%str1%" does not begin with "%str2%". ) goto :EOF

matchcontain

echo. set curr=0&set exist=0

scanchrloop

if "!str1:~%curr%,%length%!"=="" ( if !exist!==0 echo "%str1%" does not contain "%str2%". goto :EOF ) if "!str1:~%curr%,%length%!"=="!str2!" ( echo "%str1%" contains "%str2%". ^(in Position %curr%^) set exist=1 ) set /a curr+=1&goto scanchrloop

matchend

echo. if "!str1:~-%length%!"=="!str2!" ( echo "%str1%" ends with "%str2%". ) else ( echo "%str1%" does not end with "%str2%". ) goto :EOF

str2_lngth

set length=0

loop

if "!str2:~%length%,1!"=="" goto :EOF set /a length+=1 goto loop

/The functions.</lang>
Output:
```"qwertyuiop" begins with "qwerty".

"qweiuoiocghiioyiocxiisfguiioiuygvd" contains "io". (in Position 6)
"qweiuoiocghiioyiocxiisfguiioiuygvd" contains "io". (in Position 12)
"qweiuoiocghiioyiocxiisfguiioiuygvd" contains "io". (in Position 15)
"qweiuoiocghiioyiocxiisfguiioiuygvd" contains "io". (in Position 26)

"blablabla" does not end with "bbla".

Press any key to continue . . .```

BBC BASIC

<lang bbcbasic> first\$ = "The fox jumps over the dog"

```     FOR test% = 1 TO 3
starts% = FN_first_starts_with_second(first\$, second\$)
IF starts% PRINT """" first\$ """ starts with """ second\$ """"
ends% = FN_first_ends_with_second(first\$, second\$)
IF ends% PRINT """" first\$ """ ends with """ second\$ """"
where% = FN_first_contains_second_where(first\$, second\$)
IF where% PRINT """" first\$ """ contains """ second\$ """ at position " ; where%
howmany% = FN_first_contains_second_howmany(first\$, second\$)
IF howmany% PRINT """" first\$ """ contains """ second\$ """ " ; howmany% " time(s)"
NEXT
DATA "The", "he", "dog"
END

DEF FN_first_starts_with_second(A\$, B\$)
= B\$ = LEFT\$(A\$, LEN(B\$))

DEF FN_first_ends_with_second(A\$, B\$)
= B\$ = RIGHT\$(A\$, LEN(B\$))

DEF FN_first_contains_second_where(A\$, B\$)
= INSTR(A\$, B\$)

DEF FN_first_contains_second_howmany(A\$, B\$)
LOCAL I%, N% : I% = 0
REPEAT
I% = INSTR(A\$, B\$, I%+1)
IF I% THEN N% += 1
UNTIL I% = 0
= N%
```

</lang>

Output:
```"The fox jumps over the dog" starts with "The"
"The fox jumps over the dog" contains "The" at position 1
"The fox jumps over the dog" contains "The" 1 time(s)
"The fox jumps over the dog" contains "he" at position 2
"The fox jumps over the dog" contains "he" 2 time(s)
"The fox jumps over the dog" ends with "dog"
"The fox jumps over the dog" contains "dog" at position 24
"The fox jumps over the dog" contains "dog" 1 time(s)```

BQN

`⍷` does much of the heavy lifting here. It is commuted with `˜` so the order of the arguments makes sense. <lang bqn>SW ← ⊑⍷˜

Contains ← ∨´⍷˜

EW ← ¯1⊑⍷˜

Locs ← /⍷˜</lang>

Usage:

<lang bqn> "abcd" SW "ab" 1

```  "abcd" SW "cd"
```

0

```  "abcd" EW "ab"
```

0

```  "abcd" EW "cd"
```

1

```  "abcd" Contains "bb"
```

0

```  "abcd" Contains "ab"
```

1

```  "abcd" Contains "bc"
```

1

```  "abab" Contains "ab"
```

1

```  "abab" Locs "ab"
```

⟨ 0 2 ⟩</lang>

Bracmat

Bracmat does pattern matching in expressions `subject:pattern` and in strings `@(subject:pattern)`. The (sub)pattern `?` is a wild card. <lang Bracmat>( (sentence="I want a number such that that number will be even.") & out\$(@(!sentence:I ?) & "sentence starts with 'I'" | "sentence does not start with 'I'") & out\$(@(!sentence:? such ?) & "sentence contains 'such'" | "sentence does not contain 'such'") & out\$(@(!sentence:? "even.") & "sentence ends with 'even.'" | "sentence does not end with 'even.'") & 0:?N & ( @(!sentence:? be (? & !N+1:?N & ~))

``` | out\$str\$("sentence contains " !N " occurrences of 'be'")
)
```

)</lang> In the last line, Bracmat is forced by the always failing node `~` to backtrack until all occurrences of 'be' are found. Thereafter the pattern match expression fails. The interesting part is the side effect: while backtracking, the accumulator `N` keeps track of how many are found.

Output:
```sentence starts with 'I'
sentence contains 'such'
sentence ends with 'even.'
sentence contains 3 occurrences of 'be'```

C

Case sensitive matching: <lang C>#include <string.h>

1. include <stdio.h>

int startsWith(const char* container, const char* target) {

``` size_t clen = strlen(container), tlen = strlen(target);
if (clen < tlen)
return 0;
return strncmp(container, target, tlen) == 0;
```

}

int endsWith(const char* container, const char* target) {

``` size_t clen = strlen(container), tlen = strlen(target);
if (clen < tlen)
return 0;
return strncmp(container + clen - tlen, target, tlen) == 0;
```

}

int doesContain(const char* container, const char* target) {

``` return strstr(container, target) != 0;
```

}

int main(void) {

``` printf("Starts with Test ( Hello,Hell ) : %d\n", startsWith("Hello","Hell"));
printf("Ends with Test ( Code,ode ) : %d\n", endsWith("Code","ode"));
```
``` return 0;
```

}</lang>

Output:
```Starts with Test ( Hello,Hell ) : 1
Ends with Test ( Code,ode ) : 1
Contains Test ( Google,msn ) : 0```

Code without using string library to demonstrate how char strings are just pointers: <lang C>#include <stdio.h>

/* returns 0 if no match, 1 if matched, -1 if matched and at end */ int s_cmp(const char *a, const char *b) {

```       char c1 = 0, c2 = 0;
while (c1 == c2) {
c1 = *(a++);
if ('\0' == (c2 = *(b++)))
return c1 == '\0' ? -1 : 1;
}
return 0;
```

}

/* returns times matched */ int s_match(const char *a, const char *b) {

```       int i = 0, count = 0;
printf("matching `%s' with `%s':\n", a, b);
```
```       while (a[i] != '\0') {
switch (s_cmp(a + i, b)) {
case -1:
printf("matched: pos %d (at end)\n\n", i);
return ++count;
case 1:
printf("matched: pos %d\n", i);
++count;
break;
}
i++;
}
printf("end match\n\n");
return count;
```

}

int main() {

```       s_match("A Short String", "ort S");
s_match("aBaBaBaBa", "aBa");
s_match("something random", "Rand");
```
```       return 0;
```

}</lang>

Output:
```matching `A Short String' with `ort S':
matched: pos 4
end match

matching `aBaBaBaBa' with `aBa':
matched: pos 0
matched: pos 2
matched: pos 4
matched: pos 6 (at end)

matching `something random' with `Rand':
end match```

C#

Works with: Mono version 2.6

<lang csharp> class Program { public static void Main (string[] args) { var value = "abcd".StartsWith("ab"); value = "abcd".EndsWith("zn"); //returns false value = "abab".Contains("bb"); //returns false value = "abab".Contains("ab"); //returns true int loc = "abab".IndexOf("bb"); //returns -1 loc = "abab".IndexOf("ab"); //returns 0 loc = "abab".IndexOf("ab",loc+1); //returns 2 } } </lang>

C++

<lang cpp>#include <string> using namespace std;

string s1="abcd"; string s2="abab"; string s3="ab"; //Beginning s1.compare(0,s3.size(),s3)==0; //End s1.compare(s1.size()-s3.size(),s3.size(),s3)==0; //Anywhere s1.find(s2)//returns string::npos int loc=s2.find(s3)//returns 0 loc=s2.find(s3,loc+1)//returns 2</lang>

Clojure

Translation of: Java

<lang clojure>(def evals '((. "abcd" startsWith "ab") (. "abcd" endsWith "zn") (. "abab" contains "bb") (. "abab" contains "ab") (. "abab" indexOf "bb") (let [loc (. "abab" indexOf "ab")] (. "abab" indexOf "ab" (dec loc)))))

user> (for [i evals] [i (eval i)]) ([(. "abcd" startsWith "ab") true] [(. "abcd" endsWith "zn") false] [(. "abab" contains "bb") false] [(. "abab" contains "ab") true] [(. "abab" indexOf "bb") -1] [(let [loc (. "abab" indexOf "ab")] (. "abab" indexOf "ab" (dec loc))) 0])</lang>

CoffeeScript

This example uses string slices, but a better implementation might use indexOf for slightly better performance.

<lang coffeescript> matchAt = (s, frag, i) ->

``` s[i...i+frag.length] == frag
```

startsWith = (s, frag) ->

``` matchAt s, frag, 0

```

endsWith = (s, frag) ->

``` matchAt s, frag, s.length - frag.length

```

matchLocations = (s, frag) ->

``` (i for i in [0..s.length - frag.length] when matchAt s, frag, i)

```

console.log startsWith "tacoloco", "taco" # true console.log startsWith "taco", "tacoloco" # false console.log startsWith "tacoloco", "talk" # false console.log endsWith "tacoloco", "loco" # true console.log endsWith "loco", "tacoloco" # false console.log endsWith "tacoloco", "yoco" # false console.log matchLocations "bababab", "bab" # [0,2,4] console.log matchLocations "xxx", "x" # [0,1,2] </lang>

Common Lisp

<lang lisp> (defun starts-with-p (str1 str2)

``` "Determine whether `str1` starts with `str2`"
(let ((p (search str2 str1)))
(and p (= 0 p))))
```

(print (starts-with-p "foobar" "foo")) ; T (print (starts-with-p "foobar" "bar")) ; NIL

(defun ends-with-p (str1 str2)

``` "Determine whether `str1` ends with `str2`"
(let ((p (mismatch str2 str1 :from-end T)))
(or (not p) (= 0 p))))
```

(print (ends-with-p "foobar" "foo")) ; NIL (print (ends-with-p "foobar" "bar")) ; T

(defun containsp (str1 str2)

``` "Determine whether `str1` contains `str2`.
Instead of just returning T, return a list of starting locations
for every occurence of `str2` in `str1`"
(unless (string-equal str2 "")
(loop for p = (search str2 str1) then (search str2 str1 :start2 (1+ p))
while p
collect p)))
```

(print (containsp "foobar" "oba")) ; (2) (print (containsp "ababaBa" "ba")) ; (1 3) (print (containsp "foobar" "x"))  ; NIL </lang>

Component Pascal

BlackBox Component Builder <lang oberon2> MODULE StringMatch; IMPORT StdLog,Strings; CONST strSize = 1024; patSize = 256;

TYPE Matcher* = POINTER TO LIMITED RECORD str: ARRAY strSize OF CHAR; pat: ARRAY patSize OF CHAR; pos: INTEGER END;

PROCEDURE NewMatcher*(IN str: ARRAY OF CHAR): Matcher; VAR m: Matcher; BEGIN NEW(m);m.str := str\$;m.pos:= 0; RETURN m END NewMatcher;

PROCEDURE (m: Matcher) Match*(IN pat: ARRAY OF CHAR): INTEGER,NEW; VAR pos: INTEGER; BEGIN m.pat := pat\$; pos := m.pos; Strings.Find(m.str,m.pat,pos,m.pos); RETURN m.pos END Match;

PROCEDURE (m: Matcher) Next*(): INTEGER, NEW; VAR pos: INTEGER; BEGIN pos := m.pos + LEN(m.pat\$); Strings.Find(m.str,m.pat,pos,m.pos); RETURN m.pos; END Next;

(* Some Helper functions based on Strings module *) PROCEDURE StartsWith(IN str: ARRAY OF CHAR;IN pat: ARRAY OF CHAR): BOOLEAN; VAR pos: INTEGER; BEGIN Strings.Find(str,pat,0,pos); RETURN pos = 0 END StartsWith;

PROCEDURE Contains(IN str: ARRAY OF CHAR;IN pat: ARRAY OF CHAR; OUT pos: INTEGER): BOOLEAN; BEGIN Strings.Find(str,pat,0,pos); RETURN pos >= 0 END Contains;

PROCEDURE EndsWith(IN str: ARRAY OF CHAR;IN pat: ARRAY OF CHAR): BOOLEAN; VAR pos: INTEGER; BEGIN Strings.Find(str,pat,0,pos); RETURN pos + LEN(pat\$) = LEN(str\$) END EndsWith;

PROCEDURE Do*; CONST aStr = "abcdefghijklmnopqrstuvwxyz"; VAR pat: ARRAY 128 OF CHAR; res: BOOLEAN; at: INTEGER; m: Matcher; BEGIN (* StartsWith *) pat := "abc"; StdLog.String(aStr + " startsWith " + pat + " :>");StdLog.Bool(StartsWith(aStr,pat));StdLog.Ln; pat := "cba"; StdLog.String(aStr + " startsWith " + pat + " :>");StdLog.Bool(StartsWith(aStr,pat));StdLog.Ln; pat := "def"; StdLog.String(aStr + " startsWith " + pat + " :>");StdLog.Bool(StartsWith(aStr,pat));StdLog.Ln; StdLog.Ln; (* Contains *) pat := 'def'; StdLog.String(aStr + " contains " + pat + " :>");StdLog.Bool(Contains(aStr,pat,at)); StdLog.String(" at: ");StdLog.Int(at);StdLog.Ln; pat := 'efd'; StdLog.String(aStr + " contains " + pat + " :>");StdLog.Bool(Contains(aStr,pat,at)); StdLog.String(" at: ");StdLog.Int(at);StdLog.Ln; pat := 'abc'; StdLog.String(aStr + " contains " + pat + " :>");StdLog.Bool(Contains(aStr,pat,at)); StdLog.String(" at: ");StdLog.Int(at);StdLog.Ln; pat := 'xyz'; StdLog.String(aStr + " contains " + pat + " :>");StdLog.Bool(Contains(aStr,pat,at)); StdLog.String(" at: ");StdLog.Int(at);StdLog.Ln; StdLog.Ln; (* EndsWith *) pat := 'xyz'; StdLog.String(aStr + " endsWith " + pat + " :>");StdLog.Bool(EndsWith(aStr,pat));StdLog.Ln; pat := 'zyx'; StdLog.String(aStr + " endsWith " + pat + " :>");StdLog.Bool(EndsWith(aStr,pat));StdLog.Ln; pat := 'abc'; StdLog.String(aStr + " endsWith " + pat + " :>");StdLog.Bool(EndsWith(aStr,pat));StdLog.Ln; pat:= 'def'; StdLog.String(aStr + " endsWith " + pat + " :>");StdLog.Bool(EndsWith(aStr,pat));StdLog.Ln; StdLog.Ln;

m := NewMatcher("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"); StdLog.String("Matching 'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz' against 'abc':> "); StdLog.Ln; StdLog.String("Match at: ");StdLog.Int(m.Match("abc"));StdLog.Ln; StdLog.String("Match at: ");StdLog.Int(m.Next());StdLog.Ln; StdLog.String("Match at: ");StdLog.Int(m.Next());StdLog.Ln END Do; END StringMatch. </lang> Execute: ^Q StringMatching.Do

Output:
```abcdefghijklmnopqrstuvwxyz startsWith abc :> \$TRUE
abcdefghijklmnopqrstuvwxyz startsWith cba :> \$FALSE
abcdefghijklmnopqrstuvwxyz startsWith def :> \$FALSE

abcdefghijklmnopqrstuvwxyz contains def :> \$TRUE at:  3
abcdefghijklmnopqrstuvwxyz contains efd :> \$FALSE at:  -1
abcdefghijklmnopqrstuvwxyz contains abc :> \$TRUE at:  0
abcdefghijklmnopqrstuvwxyz contains xyz :> \$TRUE at:  23

abcdefghijklmnopqrstuvwxyz endsWith xyz :> \$TRUE
abcdefghijklmnopqrstuvwxyz endsWith zyx :> \$FALSE
abcdefghijklmnopqrstuvwxyz endsWith abc :> \$FALSE
abcdefghijklmnopqrstuvwxyz endsWith def :> \$FALSE

Matching 'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz' against 'abc':>
Match at:  0
Match at:  26
Match at:  -1
```

D

<lang d>void main() {

```   import std.stdio;
import std.algorithm: startsWith, endsWith, find, countUntil;
```
```   "abcd".startsWith("ab").writeln;      // true
"abcd".endsWith("zn").writeln;        // false
"abab".find("bb").writeln;            // empty array (no match)
"abcd".find("bc").writeln;            // "bcd" (substring start
//        at match)
"abab".countUntil("bb").writeln;      // -1 (no match)
"abab".countUntil("ba").writeln;      //  1 (index of 1st match)
```
```   // std.algorithm.startsWith also works on arrays and ranges:
[1, 2, 3].countUntil(3).writeln;      //  2
[1, 2, 3].countUntil([2, 3]).writeln; //  1
```

}</lang>

Output:
```true
false

bcd
-1
1
2
1```

DCL

<lang DCL>\$ first_string = p1 \$ length_of_first_string = f\$length( first_string ) \$ second_string = p2 \$ length_of_second_string = f\$length( second_string ) \$ offset = f\$locate( second_string, first_string ) \$ if offset .eq. 0 \$ then \$ write sys\$output "first string starts with second string" \$ else \$ write sys\$output "first string does not start with second string" \$ endif \$ if offset .ne. length_of_first_string \$ then \$ write sys\$output "first string contains the second string at location ", offset \$ else \$ write sys\$output "first string does not contain the second string at any location" \$ endif \$ temp = f\$extract( length_of_first_string - length_of_second_string, length_of_second_string, first_string ) \$ if second_string .eqs. temp \$ then \$ write sys\$output "first string ends with the second string" \$ else \$ write sys\$output "first string does not end with the second string" \$ endif</lang>

Output:
```\$ @string_matching efabcdef ef
first string starts with second string
first string contains the second string at location 0
first string ends with the second string
\$ @string_matching efabcdef ab
first string contains the second string at location 2
first string does not end with the second string
\$ @string_matching efabcdef def
first string contains the second string at location 5
first string ends with the second string
\$ @string_matching efabcdef defx
first string does not contain the second string at any location
first string does not end with the second string```

Delphi

<lang Delphi>program CharacterMatching;

{\$APPTYPE CONSOLE}

uses StrUtils;

begin

``` WriteLn(AnsiStartsText('ab', 'abcd')); // True
WriteLn(AnsiEndsText('zn', 'abcd')); // False
WriteLn(AnsiContainsText('abcd', 'bb')); // False
Writeln(AnsiContainsText('abcd', 'ab')); // True
WriteLn(Pos('ab', 'abcd')); // 1
```

end.</lang>

Dyalect

<lang Dyalect>var value = "abcd".StartsWith("ab") value = "abcd".EndsWith("zn") //returns false value = "abab".Contains("bb") //returns false value = "abab".Contains("ab") //returns true var loc = "abab".IndexOf("bb") //returns -1 loc = "abab".IndexOf("ab") //returns 0</lang>

E

<lang e>def f(string1, string2) {

```   println(string1.startsWith(string2))

var index := 0
while ((index := string1.startOf(string2, index)) != -1) {
println(`at \$index`)
index += 1
}
```
```   println(string1.endsWith(string2))
```

}</lang>

EchoLisp

<lang lisp> (string-suffix? "nette" "Antoinette") → #t (string-prefix? "Simon" "Simon & Garfunkel") → #t

(string-match "Antoinette" "net") → #t ;; contains (string-index "net" "Antoinette") → 5  ;; substring location </lang>

Elena

ELENA 4.x : <lang elena>import extensions;

public program() {

```   var s := "abcd";

console.printLine(s," starts with ab: ",s.startingWith:"ab");
console.printLine(s," starts with cd: ",s.startingWith:"cd");

console.printLine(s," ends with ab: ",s.endingWith:"ab");
console.printLine(s," ends with cd: ",s.endingWith:"cd");

console.printLine(s," contains ab: ",s.containing:"ab");
console.printLine(s," contains bc: ",s.containing:"bc");
console.printLine(s," contains cd: ",s.containing:"cd");
console.printLine(s," contains az: ",s.containing:"az");

console.printLine(s," index of az: ",s.indexOf(0, "az"));
console.printLine(s," index of cd: ",s.indexOf(0, "cd"));
console.printLine(s," index of bc: ",s.indexOf(0, "bc"));
console.printLine(s," index of ab: ",s.indexOf(0, "ab"));

```

}</lang>

Elixir

The String module has functions that cover the base requirements. <lang elixir>s1 = "abcd" s2 = "adab" s3 = "ab"

String.starts_with?(s1, s3)

1. => true

String.starts_with?(s2, s3)

1. => false

String.contains?(s1, s3)

1. => true

String.contains?(s2, s3)

1. => true

String.ends_with?(s1, s3)

1. => false

String.ends_with?(s2, s3)

1. => true

1. Optional requirements:

Regex.run(~r/#{s3}/, s1, return: :index)

1. => [{0, 2}]

Regex.run(~r/#{s3}/, s2, return: :index)

1. => [{2, 2}]

Regex.scan(~r/#{s3}/, "abcabc", return: :index)

1. => [[{0, 2}], [{3, 2}]]</lang>

Emacs Lisp

<lang Lisp>(defun string-contains (needle haystack)

``` (string-match (regexp-quote needle) haystack))
```

(string-prefix-p "before" "before center after") ;=> t (string-contains "before" "before center after") ;=> 0 (string-suffix-p "before" "before center after") ;=> nil

(string-prefix-p "center" "before center after") ;=> nil (string-contains "center" "before center after") ;=> 7 (string-suffix-p "center" "before center after") ;=> nil

(string-prefix-p "after" "before center after") ;=> nil (string-contains "after" "before center after") ;=> 14 (string-suffix-p "after" "before center after") ;=> t</lang>

Erlang

<lang erlang> -module(character_matching). -export([starts_with/2,ends_with/2,contains/2]).

%% Both starts_with and ends_with are mappings to 'lists:prefix/2' and %% 'lists:suffix/2', respectively.

starts_with(S1,S2) ->

```   lists:prefix(S2,S1).
```

ends_with(S1,S2) ->

```   lists:suffix(S2,S1).
```

contains(S1,S2) ->

```   contains(S1,S2,1,[]).
```

%% While S1 is at least as long as S2 we check if S2 is its prefix, %% storing the result if it is. When S1 is shorter than S2, we return %% the result. NB: this will work on any arbitrary list in erlang %% since it makes no distinction between strings and lists. contains([_|T]=S1,S2,N,Acc) when length(S2) =< length(S1) ->

```   case starts_with(S1,S2) of
true ->
contains(T,S2,N+1,[N|Acc]);
false ->
contains(T,S2,N+1,Acc)
end;
```

contains(_S1,_S2,_N,Acc) ->

```   Acc.
```

</lang>

Euphoria

<lang euphoria>sequence first, second integer x

first = "qwertyuiop"

-- Determining if the first string starts with second string second = "qwerty" if match(second, first) = 1 then

```   printf(1, "'%s' starts with '%s'\n", {first, second})
```

else

```   printf(1, "'%s' does not start with '%s'\n", {first, second})
```

end if

-- Determining if the first string contains the second string at any location -- Print the location of the match for part 2 second = "wert" x = match(second, first) if x then

```   printf(1, "'%s' contains '%s' at position %d\n", {first, second, x})
```

else

```   printf(1, "'%s' does not contain '%s'\n", {first, second})
```

end if

-- Determining if the first string ends with the second string second = "uio" if length(second)<=length(first) and match_from(second, first, length(first)-length(second)+1) then

```   printf(1, "'%s' ends with '%s'\n", {first, second})
```

else

```   printf(1, "'%s' does not end with '%s'\n", {first, second})
```

end if</lang>

Output:
```'qwertyuiop' starts with 'qwerty'
'qwertyuiop' contains 'wert' at position 2
'qwertyuiop' does not end with 'uio'
```

F#

<lang fsharp>[<EntryPoint>] let main args =

```   let text = "一二三四五六七八九十"
let starts = "一二"
let ends = "九十"
let contains = "五六"
let notContains = "百"
```
```   printfn "text = %A" text
printfn "starts with %A: %A" starts (text.StartsWith(starts))
printfn "starts with %A: %A" ends (text.StartsWith(ends))
printfn "ends with %A: %A" ends (text.EndsWith(ends))
printfn "ends with %A: %A" starts (text.EndsWith(starts))
printfn "contains %A: %A" contains (text.Contains(contains))
printfn "contains %A: %A" notContains (text.Contains(notContains))
printfn "substring %A begins at position %d (zero-based)" contains (text.IndexOf(contains))
let text2 = text + text
printfn "text = %A" text2
Seq.unfold (fun (n : int) ->
let idx = text2.IndexOf(contains, n)
if idx < 0 then None else Some (idx, idx+1)) 0
|> Seq.iter (printfn "substring %A begins at position %d (zero-based)" contains)
0</lang>
```
Output:
```text = "一二三四五六七八九十"
starts with "一二": true
starts with "九十": false
ends with "九十": true
ends with "一二": false
contains "五六": true
contains "百": false
substring "五六" begins at position 4 (zero-based)
text = "一二三四五六七八九十一二三四五六七八九十"
substring "五六" begins at position 4 (zero-based)
substring "五六" begins at position 14 (zero-based)```

Factor

Does `cheesecake` start with `cheese`? <lang factor>"cheesecake" "cheese" head?  ! t</lang> Does `cheesecake` contain `sec` at any location? <lang factor>"sec" "cheesecake" subseq?  ! t</lang> Does `cheesecake` end with `cake`? <lang factor>"cheesecake" "cake" tail?  ! t</lang> Where in `cheesecake` is the leftmost `sec`? <lang factor>"sec" "cheesecake" subseq-start  ! 4</lang> Where in `Mississippi` are all occurrences of `iss`? <lang factor>USE: regexp "Mississippi" "iss" <regexp> all-matching-slices [ from>> ] map  ! { 1 4 }</lang>

Falcon

'VBA/Python programmer's approach. I'm just a junior Falconeer but this code seems falconic <lang falcon> /* created by Aykayayciti Earl Lamont Montgomery April 9th, 2018 */

s1 = "Naig Ialocin Olracnaig" s2 = "Naig"

var = s1.startsWith(s2) ? s1 + " starts with " + s2 : s1 + " does not start with " + s2 > var

s2 = "loc" var = s2 in s1 ? @ "\$s1 contains \$s2" : @ "\$s1 does not contain \$s2" > var

> s1.endsWith(s2) ? @ "s1 ends with \$s2" : @ "\$s1 does not end with \$s2" </lang>

Output:
```Naig Ialocin Olracnaig starts with Naig
Naig Ialocin Olracnaig contains loc
Naig Ialocin Olracnaig does not end with loc
[Finished in 1.2s]
```

Fantom

Fantom provides several self-explanatory string-matching methods:

• `startsWith`
• `endsWith`
• `contains`
• `index` (takes an optional index, for the start position)
• `indexIgnoreCase` (like above, ignoring case for ASCII characters)
• `indexr` (start search from end of string, with an optional index)
• `indexrIgnoreCase` (like above, ignoring case for ASCII characters)

<lang fantom> class Main {

``` public static Void main ()
{
string := "Fantom Language"
echo ("String is: " + string)
echo ("does string contain 'age'? " + string.contains("age"))
echo ("does string contain 'page'? " + string.contains("page"))
echo ("does string end with 'Fantom'? " + string.endsWith("Fantom"))
echo ("does string end with 'Language'? " + string.endsWith("Language"))
```
```   echo ("Location of 'age' is: " + string.index("age"))
posn := string.index ("an")
echo ("First location of 'an' is: " + posn)
posn = string.index ("an", posn+1)
echo ("Second location of 'an' is: " + posn)
posn = string.index ("an", posn+1)
if (posn == null) echo ("No third location of 'an'")
}
```

} </lang>

Output:
```String is: Fantom Language
does string contain 'age'? true
does string contain 'page'? false
does string end with 'Fantom'? false
does string end with 'Language'? true
Location of 'age' is: 12
First location of 'an' is: 1
Second location of 'an' is: 8
No third location of 'an'
```

FBSL

<lang qbasic>#APPTYPE CONSOLE

DIM s = "roko, mat jane do"

IF LEFT(s, 4) = "roko" THEN PRINT STRENC(s), " starts with ", STRENC("roko") IF INSTR(s, "mat") THEN PRINT STRENC(s), " contains ", STRENC("mat"), " at ", INSTR IF RIGHT(s, 2) = "do" THEN PRINT STRENC(s), " ends with ", STRENC("do") PRINT STRENC(s), " contains ", STRENC("o"), " at the following locations:", InstrEx(s, "o")

PAUSE

SUB InstrEx(mane, match)

```   INSTR = 0
WHILE INSTR(mane, match, INSTR + 1): PRINT " ", INSTR;: WEND
```

END SUB </lang>

Output:
```"roko, mat jane do" starts with "roko"
"roko, mat jane do" contains "mat" at 7
"roko, mat jane do" ends with "do"
"roko, mat jane do" contains "o" at the following locations: 2 4 17

Press any key to continue...```

Forth

<lang forth>: starts-with ( a l a2 l2 -- ? )

``` tuck 2>r min 2r> compare 0= ;
```
ends-with ( a l a2 l2 -- ? )
``` tuck 2>r negate over + 0 max /string 2r> compare 0= ;
```

\ use SEARCH ( a l a2 l2 -- a3 l3 ? ) for contains</lang>

Fortran

Fortran does not offer a string type, but since F77 it has been possible to use a CHARACTER variable, of some specified size, whose size may be accessed via the LEN function. When passed as a parameter, a secret additional parameter specifies its size and so string-like usage is possible. Character matching is case sensitive, and, trailing spaces are ignored so that "xx" and "xx " are deemed equal. The function INDEX(text,target) determines the first index in text where target matches, and returns zero if there is no such match. Unfortunately, the function does not allow the specification of a starting position for a search, as to find any second and further matches. One must specify something like `INDEX(text(5:),target)` to start with position five, and then deal with the resulting offsets needed to relate the result to positions within the parameter. On the other hand, since there is no "length" conjoined to the text such substring selections can be made without copying the text to a work area, unlike the `copy(text,start,stop)` equivalent of Pascal for example. Some Fortran compilers do offer a starting point, and also an option to search backwards from the end, but these facilities are not guaranteed. Similarly, INDEX is only made available for CHARACTER searching, even though it could easily be generalised to other types.

A second problem is presented by the possibility that a logical expression such as `L.LT.0 .OR. etc.` will always or might possibly or in certain constructions but not others be fully evaluated, which is to say that the etc will be evaluated even though L < 0 is true so that the result is determined. And in this case, evaluating the etc will cause trouble because the indexing won't work! To be safe, therefore, a rather lame two-stage test is required - though optimising compilers might well shift code around anyway.

In the case of STARTS, these annoyances can be left to the INDEX function rather than comparing the start of A against B. At the cost of it searching the whole of A if B is not at the start. Otherwise, it would be the mirror of ENDS.

<lang Fortran>

```     SUBROUTINE STARTS(A,B)	!Text A starts with text B?
CHARACTER*(*) A,B
IF (INDEX(A,B).EQ.1) THEN	!Searches A to find B.
WRITE (6,*) ">",A,"< starts with >",B,"<"
ELSE
END IF
END SUBROUTINE STARTS
```
```     SUBROUTINE HAS(A,B)	!Text B appears somewhere in text A?
CHARACTER*(*) A,B
INTEGER L
L = INDEX(A,B)		!The first position in A where B matches.
IF (L.LE.0) THEN
WRITE (6,*) ">",A,"< does not contain >",B,"<"
ELSE
WRITE (6,*) ">",A,"< contains a >",B,"<, offset",L
END IF
END SUBROUTINE HAS
```
```     SUBROUTINE ENDS(A,B)	!Text A ends with text B.
CHARACTER*(*) A,B
INTEGER L
L = LEN(A) - LEN(B)	!Find the tail end of A that B might match.
IF (L.LT.0) THEN	!Dare not use an OR, because of full evaluation risks.
WRITE (6,*) ">",A,"< is too short to end with >",B,"<"	!Might as well have a special message.
ELSE IF (A(L + 1:L + LEN(B)).NE.B) THEN	!Otherwise, it is safe to look.
WRITE (6,*) ">",A,"< does not end with >",B,"<"
ELSE
WRITE (6,*) ">",A,"< ends with >",B,"<"
END IF
END SUBROUTINE ENDS
```
```     CALL STARTS("This","is")
CALL STARTS("Theory","The")
CALL HAS("Bananas","an")
CALL ENDS("Banana","an")
CALL ENDS("Banana","na")
CALL ENDS("Brief","Much longer")
END
```

</lang> Output: text strings are bounded by >etc.< in case of leading or trailing spaces.

``` >This< does not start with >is<
>Theory< starts with >The<
>Bananas< contains a >an<, offset           2
>Banana< does not end with >an<
>Banana< ends with >na<
>Brief< is too short to end with >Much longer<
```

Similar program using modern Fortran style <lang Fortran> !----------------------------------------------------------------------- !Main program string_matching !----------------------------------------------------------------------- program string_matching

```  implicit none
character(len=*), parameter :: fmt= '(I0)'
write(*,fmt) starts("this","is")
write(*,fmt) starts("theory","the")
write(*,fmt) has("bananas","an")
write(*,fmt) ends("banana","an")
write(*,fmt) ends("banana","na")
write(*,fmt) ends("brief","much longer")
```
```contains
!     Determining if the first string starts with second string
implicit none
character(len=*), intent(in) :: string1
character(len=*), intent(in) :: string2
if(len(string2)>len(string1)) return
end function starts
!     Determining if the first string contains the second string at any location
implicit none
character(len=*), intent(in) :: string1
character(len=*), intent(in) :: string2
character(len=:),allocatable :: temp
character(len=*), parameter :: fmt= '(A6,X,I0)'
if(len(string2)>len(string1)) return
!     Print the location of the match for part 2
!     Handle multiple occurrences of a string for part 2.
!          deallocate(temp)
temp = string1(add+1:) ! auto reallocation
enddo
end function has
!     Determining if the first string ends with the second string
implicit none
character(len=*), intent(in) :: string1
character(len=*), intent(in) :: string2
if(len(string2)>len(string1)) return
end function ends
```

end program string_matching </lang> Output: false = 0, true = 1 ( + multiple occurrences if applicable)

```0
1
at  2
at  4
1
0
1
0
```

In recent standards of Fortran strings as intrinsic first-class type and many intrinsic procedures for strings manipulation have been added.

FreeBASIC

<lang freebasic>' FB 1.05.0 Win64

Dim As String s1 = "abracadabra" Dim As String s2 = "abra" Print "First string  : "; s1 Print "Second string : "; s2 Print Print "First string begins with second string : "; CBool(s2 = Left(s1, Len(s2))) Dim As Integer i1 = Instr(s1, s2) Dim As Integer i2 Print "First string contains second string  : "; If i1 Then

``` Print "at index"; i1;
i2 = Instr(i1 + Len(s2), s1, s2)
If i2 Then
Print " and at index"; i2
Else
Print
End If
```

Else

``` Print "false";
```

End If Print "First string ends with second string  : "; CBool(s2 = Right(s1, Len(s2))) Print Print "Press any key to quit" Sleep</lang>

Output:
```First string  : abracadabra
Second string : abra

First string begins with second string : true
First string contains second string    : at index 1 and at index 8
First string ends with second string   : true
```

Gambas

Click this link to run this code <lang gambas>Public Sub Main() Dim sString1 As String = "Hello world" Dim sString2 As String = "Hello"

Print sString1 Begins Left(sString2, 5) 'Determine if the first string starts with second string If InStr(sString1, sString2) Then Print "True" Else Print "False" 'Determine if the first string contains the second string at any location Print sString1 Ends Left(sString2, 5) 'Determine if the first string ends with the second string

End</lang> Output:

```True
True
False
```

GML

Translation of: BASIC

<lang GML>#define charMatch {

```   first = "qwertyuiop";
```
```   // Determining if the first string starts with second string
second = "qwerty";
if (string_pos(second, first) > 0) {
show_message("'" + first + "' starts with '" + second + "'");
} else {
show_message("'" + first + "' does not start with '" + second + "'");
}
```
```   second = "wert"
// Determining if the first string contains the second string at any location
// Print the location of the match for part 2
if (string_pos(second, first) > 0) {
show_message("'" + first + "' contains '" + second + "' at position " + string(x));
} else {
show_message("'" + first + "' does not contain '" + second + "'");
}
// Handle multiple occurrences of a string for part 2.
x = string_count(second, first);
show_message("'" + first + "' contains " + string(x) + " instances of '" + second + "'");
```

// Determining if the first string ends with the second string

```   second = "random garbage"
temp = string_copy(first,
(string_length(first) - string_length(second)) + 1,
string_length(second));
if (temp == second) {
show_message("'" + first + "' ends with '" + second + "'");
} else {
show_message("'" + first + "' does not end with '" + second + "'");
}
```

}</lang>

Output:
(in message boxes, 1 per line)
```'qwertyuiop' starts with 'qwerty'
'qwertyuiop' contains 'wert' at position 0
'qwertyuiop' contains 1 instances of 'wert'
'qwertyuiop' does not end with 'random garbage'
```

Go

<lang go>package main

import (

```   "fmt"
"strings"
```

)

func match(first, second string) {

```   fmt.Printf("1. %s starts with %s: %t\n",
first, second, strings.HasPrefix(first, second))
i := strings.Index(first, second)
fmt.Printf("2. %s contains %s: %t,\n", first, second, i >= 0)
if i >= 0 {
fmt.Printf("2.1. at location %d,\n", i)
for start := i+1;; {
if i = strings.Index(first[start:], second); i < 0 {
break
}
fmt.Printf("2.2. at location %d,\n", start+i)
start += i+1
}
fmt.Println("2.2. and that's all")
}
fmt.Printf("3. %s ends with %s: %t\n",
first, second, strings.HasSuffix(first, second))
```

}

func main() {

```   match("abracadabra", "abr")
```

}</lang>

Output:
```1. abracadabra starts with abr: true
2.1. at location 0,
2.2. at location 7,
2.2. and that's all
3. abracadabra ends with abr: false
```

Groovy

Examples: <lang groovy>assert "abcd".startsWith("ab") assert ! "abcd".startsWith("zn") assert "abcd".endsWith("cd") assert ! "abcd".endsWith("zn") assert "abab".contains("ba") assert ! "abab".contains("bb")

assert "abab".indexOf("bb") == -1 // not found flag assert "abab".indexOf("ab") == 0

def indicesOf = { string, substring ->

```   if (!string) { return [] }
def indices = [-1]
while (true) {
indices << string.indexOf(substring, indices.last()+1)
if (indices.last() == -1) break
}
indices[1..<(indices.size()-1)]
```

} assert indicesOf("abab", "ab") == [0, 2] assert indicesOf("abab", "ba") == [1] assert indicesOf("abab", "xy") == []</lang>

All assertions pass, so there is no output.

<lang haskell>> import Data.List > "abc" `isPrefixOf` "abcdefg" True > "efg" `isSuffixOf` "abcdefg" True > "bcd" `isInfixOf` "abcdefg" True > "abc" `isInfixOf` "abcdefg" -- Prefixes and suffixes are also infixes True > let infixes a b = findIndices (isPrefixOf a) \$ tails b > infixes "ab" "abcdefabqqab" [0,6,10]</lang>

Icon and Unicon

<lang Icon>procedure main()

```  write("Matching s2 :=",image(s2 := "ab")," within s1:= ",image(s1 := "abcdabab"))

write("Test #1 beginning ",if match(s2,s1) then "matches " else "failed")
writes("Test #2 all matches at positions [")
every writes(" ",find(s2,s1)|"]\n")
write("Test #3 ending ", if s1[0-:*s2] == s2 then "matches" else "fails")

```

end</lang>

Output:
```Matching s2 :="ab" within s1:= "abcdabab"
Test #1 beginning matches
Test #2 all matches at positions [ 1 5 7 ]
Test #3 ending matches```

J

<lang j>startswith=: ] -: ({.~ #) contains=: +./@:E.~ endswith=: ] -: ({.~ -@#)</lang>

Example use:

<lang j> 'abcd' startswith 'ab' 1

```  'abcd' startswith 'cd'
```

0

```  'abcd' endswith 'ab'
```

0

```  'abcd' endswith 'cd'
```

1

```  'abcd' contains 'bb'
```

0

```  'abcd' contains 'ab'
```

1

```  'abcd' contains 'bc'
```

1

```  'abab' contains 'ab'
```

1

```  'abab' I.@E.~ 'ab'       NB. find starting indicies
```

0 2</lang>

Note that these verbs contain no constraints restricting them to sequences of characters and so also apply to arrays of type other than character: <lang j> 0 1 2 3 startswith 0 1 NB. integer 1

```  4.2 5.1 1.3 9 3 contains 1.3 4.2     NB. floating point
```

0

```  4.2 5.1 1.3 4.2 9 3 contains 1.3 4.2
```

1</lang>

Java

<lang java>"abcd".startsWith("ab") //returns true "abcd".endsWith("zn") //returns false "abab".contains("bb") //returns false "abab".contains("ab") //returns true int loc = "abab".indexOf("bb") //returns -1 loc = "abab".indexOf("ab") //returns 0 loc = "abab".indexOf("ab",loc+1) //returns 2</lang>

// -----------------------------------------------------------// public class JavaApplication6 {

```   public static void main(String[] args) {
String strOne = "complexity";
String strTwo = "udacity";
```
```       //
stringMatch(strOne, strTwo);
```
```   }
```
```   public static void stringMatch(String one, String two) {
boolean match = false;
if (one.charAt(0) == two.charAt(0)) {
System.out.println(match = true);   // returns true
} else {
System.out.println(match);       // returns false
}
for (int i = 0; i < two.length(); i++) {
int temp = i;
for (int x = 0; x < one.length(); x++) {
if (two.charAt(temp) == one.charAt(x)) {
System.out.println(match = true);    //returns true
i = two.length();
}
}
}
int num1 = one.length() - 1;
int num2 = two.length() - 1;
if (one.charAt(num1) == two.charAt(num2)) {
System.out.println(match = true);
} else {
System.out.println(match = false);
}
}
```

}

JavaScript

<lang javascript>var stringA = "tacoloco"

``` , stringB = "co"
, q1, q2, q2multi, m
, q2matches = []
```

// stringA starts with stringB q1 = stringA.substring(0, stringB.length) == stringB

// stringA contains stringB q2 = stringA.indexOf(stringB)

// multiple matches q2multi = new RegExp(stringB,'g')

while(m = q2multi.exec(stringA)){ q2matches.push(m.index) }

// stringA ends with stringB q3 = stringA.substr(-stringB.length) == stringB

console.log("1: Does '"+stringA+"' start with '"+stringB+"'? " + ( q1 ? "Yes." : "No.")) console.log("2: Is '"+stringB+"' contained in '"+stringA+"'? " + (~q2 ? "Yes, at index "+q2+"." : "No.")) if (~q2 && q2matches.length > 1){ console.log(" In fact, it happens "+q2matches.length+" times within '"+stringA+"', at index"+(q2matches.length > 1 ? "es" : "")+" "+q2matches.join(', ')+".") } console.log("3: Does '"+stringA+"' end with '"+stringB+"'? " + ( q3 ? "Yes." : "No."))</lang>

Output:
```1: Does 'tacoloco' start with 'co'? No.
2: Is 'co' contained in 'tacoloco'? Yes, at index 2.
In fact, it happens 2 times within 'tacoloco', at indexes 2, 6.
3: Does 'tacoloco' end with 'co'? Yes.```

jq

Using the builtins of jq 1.4 and later: <lang jq># startswith/1 is boolean: "abc" | startswith("ab")

1. => true</lang>

<lang jq># index/1 returns the index or null,

1. so the jq test "if index(_) then ...." can be used
2. without any type conversion.

"abcd" | index( "bc")

1. => 1</lang>

<lang jq># endswith/1 is also boolean: "abc" | endswith("bc")

1. => true</lang>

Using the regex functions available in jq 1.5: <lang jq>"abc" | test( "^ab")

"abcd" | test("bc")

"abcd" | test("cd\$")</lang>

Multiple Occurrences

To determine all the indices of one string in another: <lang sh># In jq 1.4 or later: jq -n '"abcdabcd" | indices("bc")' [

``` 1,
5
```

]</lang>

In jq 1.5, the regex function match/1 can also be used: <lang sh>\$ jq -n '"abcdabcd" | match("bc"; "g") | .offset' 1 5</lang>

Julia

<lang julia> startswith("abcd","ab") #returns true findfirst("ab", "abcd") #returns 1:2, indices range where string was found endswith("abcd","zn") #returns false match(r"ab","abcd") != Nothing #returns true where 1st arg is regex string for r in eachmatch(r"ab","abab") println(r.offset) end #returns 1, then 3 matching the two starting indices where the substring was found </lang>

K

<lang k>startswith: {:[0<#p:_ss[x;y];~*p;0]} endswith: {0=(-#y)+(#x)-*_ss[x;y]} contains: {0<#_ss[x;y]}</lang>

Example:

<lang k> startswith["abcd";"ab"] 1

``` startswith["abcd";"bc"]
```

0

``` endswith["abcd";"cd"]
```

1

``` endswith["abcd";"bc"]
```

0

``` contains["abcdef";"cde"]
```

1

``` contains["abcdef";"bdef"]
```

0

``` _ss["abcdabceabc";"abc"]    / location of matches
```

0 4 8</lang>

Kotlin

<lang scala>// version 1.0.6

fun main(args: Array<String>) {

```   val s1 = "abracadabra"
val s2 = "abra"
println("\$s1 begins with \$s2 : \${s1.startsWith(s2)}")
println("\$s1 ends with \$s2   : \${s1.endsWith(s2)}")
val b  = s2 in s1
print("\$s1 contains \$s2    : \$b")
if (b) println(" at locations \${s1.indexOf(s2) + 1} and \${s1.lastIndexOf(s2) + 1}")
else println()
```

}</lang>

Output:
```abracadabra begins with abra : true
abracadabra ends with abra   : true
abracadabra contains abra    : true at locations 1 and 8
```

Ksh

<lang ksh>

1. !/bin/ksh

exec 2> /tmp/String_matching.err

1. String matching
2. # 1. Determine if the first string starts with second string.
3. # 2. Determine if the first string contains the second string at any location
4. # 3. Determine if the first string ends with the second string
5. # 4. Print the location of the match for part 2
6. # 5. Handle multiple occurrences of a string for part 2
1. # Variables:

typeset -a bounds=( [0]="no Match" [1]="Starts with" [255]="Ends with" )

typeset -a string=( "Hello" "hello world" "William Williams" "Yabba dabba do" ) typeset -a substr=( "Hell" "Do" "abba" "Will" "orld" )

1. # Functions:
2. # Function _bounds(str, substr) - return 1 for starts with 255 for endswith

function _bounds { typeset _str ; _str="\$1" typeset _sub ; _sub="\$2"

typeset _FALSE _STARTS _ENDS ; integer _FALSE=0 _STARTS=1 _ENDS=255

[[ "\${_str}" == "\${_sub}"* ]] && return \${_STARTS} [[ "\${_str}" == *"\${_sub}" ]] && return \${_ENDS} return \${_FALSE} }

1. # Function _contains(str, substr) - return 0 no match arr[pos1 ... posn]

function _contains { typeset _str ; _str="\$1" typeset _sub ; _sub="\$2" typeset _arr ; nameref _arr="\$3"

typeset _FALSE _TRUE _i _match _buff ; integer _FALSE=0 _TRUE=1 _i _match

[[ "\${_str}" != *"\${_sub}"* ]] && return \${_FALSE}

for ((_i=0; _i<=\${#_str}-\${#_sub}; _i++)); do _buff=\${_str:\${_i}:\$((\${#_str}-_i))} [[ \${_buff} != \${_buff#\${_sub}} ]] && _arr+=( \$(( _i+1 )) ) done return \${_TRUE} }

```######
```
1. main #
```######
```

integer i j rc typeset -a posarr

for ((i=0; i<\${#string[*]}; i++)); do for ((j=0; j<\${#substr[*]}; j++)); do _bounds "\${string[i]}" "\${substr[j]}" ; rc=\$? print "\${string[i]} \${bounds[rc]} \${substr[j]}"

_contains "\${string[i]}" "\${substr[j]}" posarr ; rc=\$? ((! rc)) && print "\${string[i]} \${substr[j]} \${bounds[rc]}es" && continue

print "\${string[i]} + \${substr[j]} \${#posarr[*]} matches at \${posarr[*]}" unset posarr ; typeset -a posarr done done</lang>

Output:
```
Hello Starts with Hell
Hello + Hell 1 matches at 1
Hello no Match Do
Hello Do no Matches
Hello no Match abba
Hello abba no Matches
Hello no Match Will
Hello Will no Matches
Hello no Match orld
Hello orld no Matches
hello world no Match Hell
hello world Hell no Matches
hello world no Match Do
hello world Do no Matches
hello world no Match abba
hello world abba no Matches
hello world no Match Will
hello world Will no Matches
hello world Ends with orld
hello world + orld 1 matches at 8
William Williams no Match Hell
William Williams Hell no Matches
William Williams no Match Do
William Williams Do no Matches
William Williams no Match abba
William Williams abba no Matches
William Williams Starts with Will
William Williams + Will 2 matches at 1 9
William Williams no Match orld
William Williams orld no Matches
Yabba dabba do no Match Hell
Yabba dabba do Hell no Matches
Yabba dabba do no Match Do
Yabba dabba do Do no Matches
Yabba dabba do no Match abba
Yabba dabba do + abba 2 matches at 2 8
Yabba dabba do no Match Will
Yabba dabba do Will no Matches
Yabba dabba do no Match orld

Yabba dabba do orld no Matches```

LabVIEW

These images solve the task's requirements in order.
This image is a VI Snippet, an executable image of LabVIEW code. The LabVIEW version is shown on the top-right hand corner. You can download it, then drag-and-drop it onto the LabVIEW block diagram from a file browser, and it will appear as runnable, editable code.

Lambdatalk

<lang Scheme> {def S.in

```{def S.in.r {lambda {:c :w :i :n}
{if {= :i :n}
then -1
else {if {W.equal? :c {W.get :i :w}}
then :i
else {S.in.r :c :w {+ :i 1} :n}}}}}
{lambda {:c :w}
{S.in.r :c :w 0 {W.length :w}}}}
```

-> S.in

{def startswith

```{lambda {:w1 :w2}
{= {S.in _ {S.replace :w2 by _ in :w1}} 0}}}
```

-> startswith

{def endswith

```{lambda {:w1 :w2}
{= {S.in _ {S.replace :w2 by _ in :w1}}
{- {W.length :w1} {W.length :w2}}}}}
```

-> endswith

{def isin

```{lambda {:w1 :w2}
{S.in _ {S.replace :w2 by _ in :w1}}}}
```

-> isin

{startswith nabuchodonosor nabu} -> true {startswith nabuchodonosor abu} -> false

{endswith nabuchodonosor sor} -> true {endswith nabuchodonosor oso} -> false

{isin nabuchodonosor oso} -> 10 // is in at 10 {isin nabuchodonosor xyz} -> -1 // is not in

</lang>

Lang5

<lang lang5>: 2array 2 compress ; : bi* '_ set dip _ execute ;  : bi@ dup bi* ;

comb "" split ;  : concat "" join ;  : dip swap '_ set execute _ ;
first 0 extract swap drop ; : flip comb reverse concat ;
contains
```   swap 'comb bi@ length do                    # create a matrix.
1 - "dup 1 1 compress rotate" dip dup 0 == if break then
loop drop length compress swap drop
"length 1 -" bi@ rot 0 0 "'2array dip" '2array bi* swap 2array slice reverse
: concat.(*)  concat ;
'concat "'concat. apply" bi* eq 1 1 compress index collapse
length if expand drop else drop 0 then ;    # r: position.
```
end-with 'flip bi@ start-with ;
start-with 'comb bi@ length rot swap iota subscript 'concat bi@ eq ;

"rosettacode" "rosetta" start-with . # 1 "rosettacode" "taco" contains . # 5 "rosettacode" "ocat" contains . # 0 "rosettacode" "edoc" end-with . # 0 "rosettacode" "code" contains . # 7</lang>

Lasso

<lang Lasso>local(

```a = 'a quick brown peanut jumped over a quick brown fox',
b = 'a quick brown'
```

)

//Determining if the first string starts with second string

1. a->beginswith(#b) // true

//Determining if the first string contains the second string at any location

1. a >> #b // true
2. a->contains(#b) // true

//Determining if the first string ends with the second string

1. a->endswith(#b) // false</lang>

Liberty BASIC

<lang lb>'1---Determining if the first string starts with second string st1\$="first string" st2\$="first" if left\$(st1\$,len(st2\$))=st2\$ then

```   print "First string starts with second string."
```

end if

'2---Determining if the first string contains the second string at any location '2.1---Print the location of the match for part 2 st1\$="Mississippi" st2\$="i" if instr(st1\$,st2\$) then

```   print "First string contains second string."
print "Second string is at location ";instr(st1\$,st2\$)
```

end if

'2.2---Handle multiple occurrences of a string for part 2. pos=instr(st1\$,st2\$) while pos

```   count=count+1
pos=instr(st1\$,st2\$,pos+len(st2\$))
```

wend print "Number of times second string appears in first string is ";count

'3---Determining if the first string ends with the second string st1\$="first string" st2\$="string" if right\$(st1\$,len(st2\$))=st2\$ then

```   print "First string ends with second string."
```

end if </lang>

Lingo

<lang lingo>a = "Hello world!" b = "Hello"

-- Determining if the first string starts with second string put a starts b -- 1

-- Determining if the first string contains the second string at any location put a contains b -- 1

-- Determining if the first string ends with the second string put a.char[a.length-b.length+1..a.length] = b -- 0

b = "world!" put a.char[a.length-b.length+1..a.length] = b -- 1

-- Print the location of the match for part 2 put offset(b, a) -- 7</lang>

Logo

<lang logo>to starts.with? :sub :thing

``` if empty? :sub [output "true]
if empty? :thing [output "false]
if not equal? first :sub first :thing [output "false]
output starts.with? butfirst :sub butfirst :thing
```

end

to ends.with? :sub :thing

``` if empty? :sub [output "true]
if empty? :thing [output "false]
if not equal? last :sub last :thing [output "false]
output ends.with? butlast :sub butlast :thing
```

end

show starts.with? "dog "doghouse  ; true show ends.with? "house "doghouse  ; true show substring? "gho "doghouse  ; true (built-in)</lang>

Lua

<lang lua>s1 = "string" s2 = "str" s3 = "ing" s4 = "xyz"

print( "s1 starts with s2: ", string.find( s1, s2 ) == 1 ) print( "s1 starts with s3: ", string.find( s1, s3 ) == 1, "\n" )

print( "s1 contains s3: ", string.find( s1, s3 ) ~= nil ) print( "s1 contains s3: ", string.find( s1, s4 ) ~= nil, "\n" )

print( "s1 ends with s2: ", select( 2, string.find( s1, s2 ) ) == string.len( s1 ) ) print( "s1 ends with s3: ", select( 2, string.find( s1, s3 ) ) == string.len( s1 ) )</lang>

M2000 Interpreter

<lang M2000 Interpreter> Module StringMatch {

```     A\$="Hello World"
Print A\$ ~ "Hello*"
Print A\$ ~ "*llo*"
p=Instr(A\$, "llo")
Print p=3
\\ Handle multiple occurance for "o"
p=Instr(A\$, "o")
While p > 0 {
Print "position:";p;{ for "o"}
p=Instr(A\$, "o", p+1)
}
Print A\$ ~ "*orld"
```

} StringMatch </lang>

Output:
```    True
True
True
position:5 for "o"
position:8 for "o"
True
```

Maple

These facilities are all to be found in the StringTools package in Maple. <lang Maple> > with( StringTools ): # bind package exports at the top-level > s := "dzrIemaWWIMidXYZwGiqkOOn": > s[1..4]; # pick a prefix

```                                "dzrI"
```

> IsPrefix( s[ 1 .. 4 ], s ); # check it

```                                 true
```

> s[ -4 .. -1 ]; # pick a suffix

```                                "kOOn"
```

> IsSuffix( s[ -4 .. -1 ], s ); # check it

```                                 true
```

> p := Search( "XYZ", s ); # find a substring

```                               p := 14
```

> s[ p .. p + 2 ]; # check

```                                "XYZ"
```

> SearchAll( [ "WWI", "XYZ" ], s ); # search for multiple patterns

```                           [8, 1], [14, 2]
```

> to 3 do s := cat( s, s ) end: length( s ); # build a longer string by repeated doubling

```                                 192
```

> p := SearchAll( "XYZ", s ); # find all occurrences

```               p := 14, 38, 62, 86, 110, 134, 158, 182
```

> {seq}( s[ i .. i + 2 ], i = p ); # check them

```                               {"XYZ"}
```

</lang> The StringTools package also contains facilities for regular expression matching, but for fixed string patterns, the Search and SearchAll tools are much faster.

Mathematica/Wolfram Language

<lang Mathematica>StartWith[x_, y_] := MemberQ[Flatten[StringPosition[x, y]], 1] EndWith[x_, y_] := MemberQ[Flatten[StringPosition[x, y]], StringLength[x]] StartWith["XYZaaabXYZaaaaXYZXYZ", "XYZ"] EndWith["XYZaaabXYZaaaaXYZXYZ", "XYZ"] StringPosition["XYZaaabXYZaaaaXYZXYZ", "XYZ"]</lang>

Output:
```True
True
{{1,3},{8,10},{15,17},{18,20}}```

MATLAB / Octave

<lang Matlab>

```  % 1. Determining if the first string starts with second string
```

strcmp(str1,str2,length(str2))

```  % 2. Determining if the first string contains the second string at any location
```

~isempty(strfind(s1,s2))

```  % 3. Determining if the first string ends with the second string
```

( (length(str1)>=length(str2)) && strcmp(str1(end+[1-length(str2):0]),str2) )

```  % 1. Print the location of the match for part 2
```

disp(strfind(s1,s2))

```  % 2. Handle multiple occurrences of a string for part 2.
```

ix = strfind(s1,s2);  % ix is a vector containing the starting positions of s2 within s1 </lang>

min

One way might be:

Works with: min version 0.19.6

<lang min>(indexof 0 ==) :starts-with? (indexof -1 !=) :contains? ((/ \$/) swap 1 insert "" join regex ("") !=) :ends-with?

"minimalistic" "min" starts-with? puts! "minimalistic" "list" contains? puts! "minimalistic" "list" ends-with? puts!</lang>

Output:
```true
true
false
```

MiniScript

We first extend the built-in string class with three new methods, and then demonstrate their use on some sample strings.

<lang MiniScript>string.startsWith = function(s)

```   return self.len >= s.len and s[:s.len] == s
```

end function

string.endsWith = function(s)

```   return self.len >= s.len and s[-s.len:] == s
```

end function

string.findAll = function(s)

```   result = []
after = null
while true
foundPos = self.indexOf(s, after)
if foundPos == null then return result
result.push foundPos
after = foundPos + s.len - 1
end while
```

end function

first = "The brown dog jumped jumped and jumped" second = "jumped"

firstQ = """" + first + """" // (first string, in quotes) secondQ = """" + second + """" doesOrNot = [" does not ", " does "]

```   print firstQ + " does not contain " + secondQ + " anywhere"
```

else

```   for pos in found
print firstQ + " is found at position " + pos + " in " + secondQ
end for
```

end if print

print firstQ + doesOrNot[first.endsWith(second)] + "end with " + secondQ</lang>

Output:
```"The brown dog jumped jumped and jumped" does start with "jumped"

"The brown dog jumped jumped and jumped" is found at position 14 in "jumped"
"The brown dog jumped jumped and jumped" is found at position 21 in "jumped"
"The brown dog jumped jumped and jumped" is found at position 32 in "jumped"

"The brown dog jumped jumped and jumped" does end with "jumped"
```

MIPS Assembly

The function below returns the zero-based index where the string pointed to by `\$a1` occurs in `\$a0`.

• If it returns strlen(`\$a0`), then `\$a1` was not found.
• If it returns 0, then `\$a0` begins with `\$a1`.
• If it returns strlen(`\$a0`)-strlen(`\$a1`), then `\$a0` ends with `\$a1`.
• Otherwise, `\$a0` contains `\$a1` starting at the specified location.

<lang mips>InString: ;input: \$a0 = ptr to string 1 ; \$a1 = ptr to string 2 ; assumes len(\$a1) <= len(\$a0) ;out: \$v0 = zero-based index where the second string is placed in the first.

;clobbers: \$t0,\$t1 subiu sp,sp,4 ;set up a stack frame of 4 bytes. sw \$a1,(sp) li \$v0,0 InString_again: lbu \$t0,(\$a0) nop beqz \$t0,InString_terminated nop

lbu \$t1,(\$a1) nop beqz \$t1,InString_terminated nop

InString_noMatch: lw \$a1,(sp) ;reset the substring pointer if the letters don't match addiu \$v0,1 ;load delay slot InString_overhead: addiu \$a0,1 b InString_Again nop InString_terminated: addiu sp,sp,4 jr ra nop</lang>

Output:

<lang mips>main: la \$a0,MyString la \$a1,Test4 jal InString nop

jal Monitor nop

shutdown: nop ;Project 64 will detect an infinite loop and close the ROM if I don't have this nop here. b shutdown nop

MyString: ;this was loaded into \$a0 .ascii "abcdefghijklmnopqrstuvwxyz" .byte 0 .align 4

each of these was loaded into \$a1 individually for testing

Test1: .ascii "abc" ;InString returned 0 .byte 0 .align 4 Test2: .ascii "xyz" ;InString returned 0x17 (decimal 23) .byte 0 .align 4 Test3: .ascii "def" ;InString returned 3 .byte 0 .align 4 Test4: .ascii "z",0 ;InString returned 0x19 (decimal 25) .byte 0 .align 4 Test5: .ascii "1",0; InString returned 0x1A (decimal 26) .byte 0 .align 4</lang>

NetRexx

<lang NetRexx>/* NetRexx */ options replace format comments java crossref savelog symbols

lipsum = x_ = 0 x_ = x_ + 1; lipsum[0] = x_; lipsum[x_] = 'Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.' x_ = x_ + 1; lipsum[0] = x_; lipsum[x_] = lipsum[1].reverse

srch = srch[1] = 'Lorem ipsum dolor sit amet' srch[2] = 'consectetur adipisicing elit' srch[3] = 'dolore magna aliqua.'

loop j_ = 1 to lipsum[0]

``` x1 = lipsum[j_].pos(srch[1])
x2 = lipsum[j_].pos(srch[2])
x3 = lipsum[j_].lastpos(srch[3])
```
``` report(x1 = 1, lipsum[j_], srch[1], 'Test string starts with search string:', 'Test string does not start with search string:')
report(x2 > 0, lipsum[j_], srch[2], 'Search string located in test string at position:' x2,  'Search string not found within test string:')
report(x3 \= srch[3].length, lipsum[j_], srch[3], 'Test string ends with search string:', 'Test string does not start with search string:')
end j_
```

many = x_ = 0 x_ = x_ + 1; many[0] = x_; many[x_] = 'How many times does "many times" occur in this string?' x_ = x_ + 1; many[0] = x_; many[x_] = 'How often does "many times" occur in this string?' x_ = x_ + 1; many[0] = x_; many[x_] = 'How often does it occur in this string?' srch[4] = 'many times'

loop j_ = 1 to many[0]

``` o_ = 0
k_ = 0
loop label dups until o_ = 0
o_ = many[j_].pos(srch[4], o_ + 1)
if o_ \= 0 then k_ = k_ + 1
end dups
report(k_ > 0, many[j_], srch[4], 'Number of times search string occurs:' k_, 'Search string not found')
end j_
```

method report(state = boolean, ts, ss, testSuccess, testFailure) public static

``` if state then say testSuccess
else          say testFailure
say '    Test string:' ts
say '  Search string:' ss
say
```
``` return
```

</lang>

NewLISP

<lang NewLISP>(setq str "abcdefbcghi")

test if str starts with "ab"

(starts-with str "ab")

find "bc" inside str

(find "bc" str)

test if str ends with "ghi"

(ends-with str "ghi")

find all positions of pattern inside str

(define (find-all-pos pattern str)

``` (let ((idx -1) (pos '()))
(while (setq idx (find pattern str 0 (+ idx 1)))
(push idx pos -1))))
```

(find-all-pos "bc" str)</lang>

Nim

<lang nim>import strutils

let s = "The quick brown fox" if s.startsWith("The quick"):

``` echo "Starts with “The quick”."
```

if s.endsWith("brown Fox"):

``` echo "Ends with “brown fox”."
```

if s.contains(" brown "):

``` echo "Contains “ brown ”."
```

if "quick" in s:

``` echo "Contains “quick”."      # Alternate form for "contains".
```

let pos = find(s, " brown ") # -1 if not found. if pos >= 0:

``` echo "“ brown ” is located at position: " & \$pos</lang>
```
Output:
```Starts with “The quick”.
Contains “ brown ”.
Contains “quick”.
“ brown ” is located at position: 9```

Objeck

<lang objeck> bundle Default {

``` class Matching {
function : Main(args : System.String[]) ~ Nil {
"abcd"->StartsWith("ab")->PrintLine(); # returns true
"abcd"->EndsWith("zn")->PrintLine(); # returns false
("abab"->Find("bb") <> -1)->PrintLine(); # returns false
("abab"->Find("ab") <> -1)->PrintLine(); # returns true
loc := "abab"->Find("bb"); # returns -1
loc := "abab"->Find("ab"); # returns 0
loc := "abab"->Find("ab", loc + 1); # returns 2
}
}
```

} </lang>

Objective-C

<lang objc>[@"abcd" hasPrefix:@"ab"] //returns true [@"abcd" hasSuffix:@"zn"] //returns false int loc = [@"abab" rangeOfString:@"bb"].location //returns -1 loc = [@"abab" rangeOfString:@"ab"].location //returns 0 loc = [@"abab" rangeOfString:@"ab" options:0 range:NSMakeRange(loc+1, [@"abab" length]-(loc+1))].location //returns 2</lang>

OCaml

<lang ocaml>let match1 s1 s2 =

``` let len1 = String.length s1
and len2 = String.length s2 in
if len1 < len2 then false else
let sub = String.sub s1 0 len2 in
(sub = s2)</lang>
```

testing in the top-level:

```# match1 "Hello" "Hello World!" ;;
- : bool = false
# match1 "Hello World!" "Hello" ;;
- : bool = true
```

<lang ocaml>let match2 s1 s2 =

``` let len1 = String.length s1
and len2 = String.length s2 in
if len1 < len2 then false else
let rec aux i =
if i < 0 then false else
let sub = String.sub s1 i len2 in
if (sub = s2) then true else aux (pred i)
in
aux (len1 - len2)</lang>
```
```# match2 "It's raining, Hello World!" "umbrella" ;;
- : bool = false
# match2 "It's raining, Hello World!" "Hello" ;;
- : bool = true
```

<lang ocaml>let match3 s1 s2 =

``` let len1 = String.length s1
and len2 = String.length s2 in
if len1 < len2 then false else
let sub = String.sub s1 (len1 - len2) len2 in
(sub = s2)</lang>
```
```# match3 "Hello World" "Hello" ;;
- : bool = false
# match3 "Hello World" "World" ;;
- : bool = true
```

<lang ocaml>let match2_loc s1 s2 =

``` let len1 = String.length s1
and len2 = String.length s2 in
if len1 < len2 then (false, -1) else
let rec aux i =
if i < 0 then (false, -1) else
let sub = String.sub s1 i len2 in
if (sub = s2) then (true, i) else aux (pred i)
in
aux (len1 - len2)</lang>
```
```# match2_loc "The sun's shining, Hello World!" "raining" ;;
- : bool * int = (false, -1)
# match2_loc "The sun's shining, Hello World!" "shining" ;;
- : bool * int = (true, 10)
```

<lang ocaml>let match2_num s1 s2 =

``` let len1 = String.length s1
and len2 = String.length s2 in
if len1 < len2 then (false, 0) else
let rec aux i n =
if i < 0 then (n <> 0, n) else
let sub = String.sub s1 i len2 in
if (sub = s2)
then aux (pred i) (succ n)
else aux (pred i) (n)
in
aux (len1 - len2) 0</lang>
```
```# match2_num "This cloud looks like a camel, \
that other cloud looks like a llama" "stone" ;;
- : bool * int = (false, 0)
# match2_num "This cloud looks like a camel, \
that other cloud looks like a llama" "cloud" ;;
- : bool * int = (true, 2)
```

Oforth

<lang Oforth>: stringMatching(s1, s2) | i |

```  s2 isAllAt(s1, 1) ifTrue: [ System.Out s1 << " begins with " << s2 << cr ]
s2 isAllAt(s1, s1 size s2 size - 1 + ) ifTrue: [ System.Out s1 << " ends with " << s2 << cr ]
```
```  s1 indexOfAll(s2) ->i
i ifNotNull: [ System.Out s1 << " includes " << s2 << " at position : " << i << cr ]
```
```  "\nAll positions : " println
1 ->i
while (s1 indexOfAllFrom(s2, i) dup ->i notNull) [
System.Out s1 << " includes " << s2 << " at position : " << i << cr
i s2 size + ->i
] ;</lang>
```
Output:
```> "arduinoardblobard", "ard" stringMatching
arduinoardblobard begins with ard
arduinoardblobard ends with ard
arduinoardblobard includes ard at position : 1

All positions :
arduinoardblobard includes ard at position : 1
arduinoardblobard includes ard at position : 8
arduinoardblobard includes ard at position : 15
```

OxygenBasic

<lang oxygenbasic> string s="sdfkjhgsdfkdfgkbopefioqwurti487sdfkrglkjfs9wrtgjglsdfkdkjcnmmb.,msfjflkjsdfk"

string f="sdfk"

string cr=chr(13)+chr(10),tab=chr(9)

string pr="FIND STRING LOCATIONS" cr cr

sys a=0, b=1, count=0, ls=len(s), lf=len(f)

do

``` a=instr b,s,f
if a=0 then exit do
count++
if a=1 then  pr+="Begins with keyword" cr
pr+=count tab a cr
if a=ls-lf+1 then pr+="Ends with keyword at " a cr
b=a+1
```

end do

pr+=cr "Total matches: " count cr

print pr

'FIND STRING LOCATIONS ' 'Begins with keyword '1 1 '2 8 '3 32 '4 51 '5 73 'Ends with keyword at 73 ' 'Total matches: 5 </lang>

PARI/GP

This meets the first but not the second of the optional requirements. Note that GP treats any nonzero value as true so the location found by contains() can be ignore if not needed. <lang parigp>startsWith(string, prefix)={

``` string=Vec(string);
prefix=Vec(prefix);
if(#prefix > #string, return(0));
for(i=1,#prefix,if(prefix[i]!=string[i], return(0)));
1
```

}; contains(string, inner)={

``` my(good);
string=Vec(string);
inner=Vec(inner);
for(i=0,#string-#inner,
good=1;
for(j=1,#inner,
if(inner[j]!=string[i+j], good=0; break)
);
if(good, return(i+1))
);
0
```

}; endsWith(string, suffix)={

``` string=Vec(string);
suffix=Vec(suffix);
if(#suffix > #string, return(0));
for(i=1,#suffix,if(prefix[i]!=string[i+#string-#suffix], return(0)));
1
```

};</lang>

Perl

Using regexes:

<lang perl>\$str1 =~ /^\Q\$str2\E/ # true if \$str1 starts with \$str2 \$str1 =~ /\Q\$str2\E/ # true if \$str1 contains \$str2 \$str1 =~ /\Q\$str2\E\$/ # true if \$str1 ends with \$str2</lang>

Using `index`:

<lang perl>index(\$str1, \$str2) == 0 # true if \$str1 starts with \$str2 index(\$str1, \$str2) != -1 # true if \$str1 contains \$str2 rindex(\$str1, \$str2) == length(\$str1) - length(\$str2) # true if \$str1 ends with \$str2</lang>

Using `substr`:

<lang perl>substr(\$str1, 0, length(\$str2)) eq \$str2 # true if \$str1 starts with \$str2 substr(\$str1, - length(\$str2)) eq \$str2 # true if \$str1 ends with \$str2</lang>

Bonus task (printing all positions where `\$str2` appears in `\$str1`):

<lang perl>print \$-[0], "\n" while \$str1 =~ /\Q\$str2\E/g; # using a regex</lang> <lang perl>my \$i = -1; print \$i, "\n" while (\$i = index \$str1, \$str2, \$i + 1) != -1; # using index</lang>

Phix

Library: Phix/basics
```constant word = "the",                                      -- (also try this with "th"/"he")
sentence = "the last thing the man said was the"
--       sentence = "thelastthingthemansaidwasthe"          -- (practically the same results)

-- A common, but potentially inefficient idiom for checking for a substring at the start is:
if match(word,sentence)=1 then
?"yes(1)"
end if
-- A more efficient method is to test the appropriate slice
if length(sentence)>=length(word)
and sentence[1..length(word)]=word then
?"yes(2)"
end if
-- Which is almost identical to checking for a word at the end
if length(sentence)>=length(word)
and sentence[-length(word)..-1]=word then
?"yes(3)"
end if
-- Or sometimes you will see this, a tiny bit more efficient:
if length(sentence)>=length(word)
and match(word,sentence,length(sentence)-length(word)+1) then
?"yes(4)"
end if
-- Finding all occurences is a snap:
integer r = match(word,sentence)
while r!=0 do
?r
r = match(word,sentence,r+1)
end while
-- or equivalently:
?match_all(word,sentence)
```
Output:
```"yes(1)"
"yes(2)"
"yes(3)"
"yes(4)"
1
16
33
{1,16,33}
```

PHP

<lang php><?php /**********************************************************************************

• This program gets needle and haystack from the caller (chm.html) (see below)
• and checks for occurrences of the needle in the haystack
• 02.05.2013 Walter Pachl
• /

\$haystack = \$_POST['haystack']; if (\$haystack==) {\$haystack='no haystack given';} \$needle = \$_POST['needle']; if (\$needle==) {\$needle='no needle given';}

function rexxpos(\$h,\$n) {

``` \$pos = strpos(\$h,\$n);
if (\$pos === false) { \$pos=-1; }
else                { \$pos=\$pos+1; }
return (\$pos);
}
```

\$pos=rexxpos(\$haystack,\$needle); \$tx1 = ""; if (\$pos==-1){ \$n=0; } // not found else { \$n=1; } // found once (so far) // Special cases if (\$pos==1){ \$tx1="needle found to be the start of the haystack"; } if (\$pos==strlen(\$haystack)-strlen(\$needle)+1)

```           { \$tx1="needle found at end of haystack"; }
```

if (\$n>0) { // look for other occurrences

``` \$pl=\$pos; // list of positions
\$p=\$pos;  //
\$x="*************************************";
\$h=\$haystack;
while (\$p>0) {
\$h=substr(\$x,0,\$p).substr(\$h,\$p);
\$p=rexxpos(\$h,\$needle);
if ( \$p>0 ) { \$n=\$n+1; \$pl=\$pl.", ".\$p; }
}
if (\$n==1) { \$txt="needle found once in haystack, position: \$pl."; }
else if (\$n==2) { \$txt="needle found twice in haystack, position(s): \$pl."; }
else            { \$txt="needle found \$n times in haystack, position(s): \$pl."; }
```

``` <head>
<title>Character Matching</title>
<meta name="author" content="Walter Pachl">
<meta name="date" content="02.05.2013">
<style>
p { font: 120% courier; }
</style>
<body>
```

Haystack: '<?php echo "\$haystack" ?>'

Needle:   '<?php echo "\$needle" ?>'

<?php echo "\$txt" ?>

<?php echo "\$tx1" ?>

``` </body>
```

</html></lang> <lang php><?php <!DOCTYPE html> <html>

``` <head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Character matching</title>
<body>
<form id="test" name="test" method="post" action="chmx.php">
```

Character matching

Given two strings, demonstrate the following 3 types of matchings:

1. Determining if the first string starts with second string
2. Determining if the first string contains the second string at any location
3. Determining if the first string ends with the second string

Optional requirements:

1. Print the location of the match(es) for part 2
2. Handle multiple occurrences of a string for part 2.

Haystack: <input type="text" name="haystack" size="80">

Needle:   <input type="text" name="needle" size="80">

Press <input name="Submit" type="submit" class="erfolg" value="CHECK"/> to invoke chmx.php.

``` </form>
</body>
```

</html></lang>

Picat

The two most common predicate to use for string matching is `find/4` (find a substring) or `append/3` (a general purpose reversible predicate for concatenating/splitting lists/strings). Both predicates are non-deterministic and can yield multiple solutions, e.g. together with `findall/2`.

<lang Picat>import util.

go =>

``` S1 = "string second",
S2 = "string",
```
``` %  - Determining if the first string starts with second string
println("Using find/4"),
if find(S1,S2,1,_) then
println("S1 starts with S2")
else
end,
```
``` println("Using append/3"),
if append(S2,_,S1) then
println("S1 starts with S2")
else
end,

% - Determining if the first string contains the second string at any location
S3 = "this is a string",
S4 = "is a",
if find(S3,S4,Start4,End4) then
printf("S3 contains S4 at pos %d..%d\n", Start4,End4)
else
println("S3 does not contain S4")
end,
```
``` % - Determining if the first string ends with the second string
S5 = "this is a string",
S6 = "string",
if find(S5,S6,Start6,S5.length) then
printf("S5 ends with S6, startpos: %d\n",Start6)
else
println("S5 does not end with S6")
end,

if append(_,S6,S5) then
println("S5 ends with S6")
else
println("S5 does not end with S6")
end,
```
``` S7 = "this is a string or a string",
S8 = "a string",
All = findall([Start8,End8], find(S7,S8,Start8,End8)),
println(positions=All),
```
``` % searching for " "
All2 = findall([Start9,End9], find(S7," ",Start9,End9)),
println(positions=All2),
nl.</lang>
```
Output:
```Using find/4
S1 starts with S2
Using append/3
S1 starts with S2
S3 contains S4 at pos 6..9
S5 ends with S6, startpos: 11
S5 ends with S6
positions = [[9,16],[21,28]]
positions = [[5,5],[8,8],[10,10],[17,17],[20,20],[22,22]]```

PicoLisp

<lang PicoLisp>: (pre? "ab" "abcd") -> "abcd"

(pre? "xy" "abcd")

-> NIL

(sub? "bc" "abcd")

-> "abcd"

(sub? "xy" "abcd")

-> NIL

(tail (chop "cd") (chop "abcd"))

-> ("c" "d")

(tail (chop "xy") (chop "abcd"))

-> NIL

(de positions (Pat Str)

```  (setq Pat (chop Pat))
(make
(for ((I . L) (chop Str) L (cdr L))
```
(positions "bc" "abcdabcd")

-> (2 6)</lang>

PL/I

<lang PL/I> /* Let s be one string, t be the other that might exist within s. */

```                                                    /* 8-1-2011 */
```

k = index(s, t); if k = 0 then put skip edit (t, ' is nowhere in sight') (a); else if k = 1 then

```  put skip edit (t, '  starts at the beginning of  ', s) (a);
```

else if k+length(t)-1 = length(s) then

```  put skip edit (t, '  is at the end of  ', s) (a);
```

else put skip edit (t, ' is within ', s) (a);

if k > 0 then put skip edit (t, ' starts at position ', k) (a); </lang>

Optional extra:

<lang PL/I> /* Handle multiple occurrences. */

```  n = 1;
do forever;
k = index(s, t, n);
if k = 0 then
do;
if n = 1 then put skip list (t, ' is nowhere in sight');
stop;
end;
else if k = 1 then
put skip edit ('<', t, '> starts at the beginning of  ', s) (a);
else if k+length(t)-1 = length(s) then
put skip edit ('<', t, '> is at the end of  ', s) (a);
else put skip edit ('<', t, '> is within  ', s) (a);
n =   k + length(t);
```
```     if k > 0 then
put skip edit ('<', t, '> starts at position ', trim(k)) (a);
else stop;
end;
```

</lang>

PowerShell

<lang Powershell> "spicywiener".StartsWith("spicy") "spicywiener".Contains("icy") "spicywiener".EndsWith("wiener") "spicywiener".IndexOf("icy") [regex]::Matches("spicywiener", "i").count </lang>

Output:
```True
True
True
2
2
```

Prolog

<lang prolog>

- system:set_prolog_flag(double_quotes,codes) .
- [library(lists)] .

%! starts_with(FIRSTz,SECONDz) % % True if `SECONDz` is the beginning of `FIRSTz` .

starts_with(FIRSTz,SECONDz)

-

lists:append(SECONDz,_,FIRSTz) .

%! contains(FIRSTz,SECONDz) % % True once if `SECONDz` is contained within `FIRSTz` at one or more positions .

contains(FIRSTz,SECONDz)

-

contains(FIRSTz,SECONDz,_) , ! .

%! contains(FIRSTz,SECONDz,NTH1) % % True if `SECONDz` is contained within `FIRSTz` at position `NTH1` .

contains(FIRSTz,SECONDz,NTH1)

-

lists:append([PREFIXz,SECONDz,_SUFFIXz_],FIRSTz) , prolog:length(PREFIXz,NTH0) , NTH1 is NTH0 + 1 .

%! ends_with(FIRSTz,SECONDz) % % True if `SECONDz` is the ending of `FIRSTz` .

ends_with(FIRSTz,SECONDz)

-

lists:append(_,SECONDz,FIRSTz) .

</lang>

Output:
```
?- starts_with("abcdef","abc") .
true .

?- starts_with("abc","abc") .
true .

?- starts_with("abc","abcd") .
false .

?- starts_with("dabc","abc") .
false .

?- starts_with("","") .
true .

?-

?- contains("abcdef","abc") .
true.

?- contains("abcdef","abc",NTH).
NTH = 1 ;
false.

?- contains("abcdef","de",NTH).
NTH = 4 ;
false.

?- contains("abcdef","f",NTH).
NTH = 6 ;
false.

?- contains("abcde","f",NTH).
false.

?- contains("","",NTH).
NTH = 1 ; % wtf ?
false.

?- contains("a","a",NTH).
NTH = 1 ; % wtf ?
false.

?-

?- ends_with("abc","abc") .
true ;
false .

?- ends_with("abc","bc") .
true ;
false .

?- ends_with("abcd","bc") .
false .

?- ends_with("","") .
true ;
false .

?-
```

PureBasic

<lang PureBasic>Procedure StartsWith(String1\$, String2\$)

``` Protected Result
If FindString(String1\$, String2\$, 1) =1 ; E.g Found in possition 1
Result =CountString(String1\$, String2\$)
EndIf
ProcedureReturn Result
```

EndProcedure

Procedure EndsWith(String1\$, String2\$)

``` Protected Result, dl=Len(String1\$)-Len(String2\$)
If dl>=0 And Right(String1\$, Len(String2\$))=String2\$
Result =CountString(String1\$, String2\$)
EndIf
ProcedureReturn Result
```

EndProcedure</lang> And a verification <lang PureBasic>If OpenConsole()

``` PrintN(Str(StartsWith("Rosettacode", "Rosetta")))           ; = 1
PrintN(Str(StartsWith("Rosettacode", "code")))              ; = 0
PrintN(Str(StartsWith("eleutherodactylus cruralis", "e")))  ; = 3
PrintN(Str(EndsWith  ("Rosettacode", "Rosetta")))  ; = 0
PrintN(Str(EndsWith  ("Rosettacode", "code")))     ; = 1
PrintN(Str(EndsWith  ("Rosettacode", "e")))        ; = 2

Print(#CRLF\$ + #CRLF\$ + "Press ENTER to exit"): Input()
CloseConsole()
```

EndIf</lang>

An alternate and more complete solution: <lang PureBasic>Procedure startsWith(string1\$, string2\$)

``` ;returns one if string1\$ starts with string2\$, otherwise returns zero
If FindString(string1\$, string2\$, 1) = 1
ProcedureReturn 1
EndIf
ProcedureReturn 0
```

EndProcedure

Procedure contains(string1\$, string2\$, location = 0)

``` ;returns the location of the next occurrence of string2\$ in string1\$ starting from location,
;or zero if no remaining occurrences of string2\$ are found in string1\$
ProcedureReturn FindString(string1\$, string2\$, location + 1)
```

EndProcedure

Procedure endsWith(string1\$, string2\$)

``` ;returns one if string1\$ ends with string2\$, otherwise returns zero
Protected ls = Len(string2\$)
If Len(string1\$) - ls >= 0 And Right(string1\$, ls) = string2\$
ProcedureReturn 1
EndIf
ProcedureReturn 0
```

EndProcedure

If OpenConsole()

``` PrintN(Str(startsWith("RosettaCode", "Rosetta")))           ; = 1, true
PrintN(Str(startsWith("RosettaCode", "Code")))              ; = 0, false

PrintN("")
PrintN(Str(contains("RosettaCode", "luck")))                ; = 0, no occurrences
Define location
Repeat
location = contains("eleutherodactylus cruralis", "e", location)
PrintN(Str(location))                                     ;display each occurrence: 1, 3, 7,  & 0 (no more occurrences)
Until location = 0

PrintN("")
PrintN(Str(endsWith  ("RosettaCode", "Rosetta")))            ; = 0, false
PrintN(Str(endsWith  ("RosettaCode", "Code")))               ; = 1, true

Print(#CRLF\$ + #CRLF\$ + "Press ENTER to exit"): Input()
CloseConsole()
```

EndIf</lang>

Output:
```1
0

0
1
3
7
0

0
1```

Python

<lang python>"abcd".startswith("ab") #returns True "abcd".endswith("zn") #returns False "bb" in "abab" #returns False "ab" in "abab" #returns True loc = "abab".find("bb") #returns -1 loc = "abab".find("ab") #returns 0 loc = "abab".find("ab",loc+1) #returns 2</lang>

QB64

<lang QB64> DefStr S DefInt P string2 = "dogs" string1 = "dogs and cats are often enemies,because dogs are stronger than cats, but cats sometimes can be friend to dogs" position = 0 pcount = 0 Print "Searching "; string2; " into "; string1 While (InStr(position, string1, string2) > 0)

```   position = InStr(position + 1, string1, string2)
pcount = pcount + 1
If position = 1 Then Print string1; "- starts with -"; string2
Print position
If position = Len(string1) - Len(string2) + 1 Then
Print string1; "- ends with -"; string2
Exit While
End If
```

Wend Print string2; " is present "; pcount; " times into "; string1 </lang>

Quackery

These work for any nests (i.e. dynamic arrays), not just strings (i.e. nests of chars).

<lang Quackery> [ tuck size split drop = ] is starts ( [ [ --> b )

``` [ tuck size negate split nip = ] is ends     ( [ [ --> b )
```
``` [ 2dup = iff true
else
[ over [] = iff false done
2dup starts iff true done
dip 2drop ]                    is contains ( [ [ --> b )

[ iff
[ say "true" ]
else
[ say "false" ] ]           is echobool  (   b -->   )

\$ "abcdefgh" \$ "abc" starts   echobool cr
\$ "abcdefgh" \$ "xyz" starts   echobool cr
\$ "abcdefgh" \$ "fgh" ends     echobool cr
\$ "abcdefgh" \$ "xyz" ends     echobool cr
\$ "abcdefgh" \$ "cde" contains echobool cr
\$ "abcdefgh" \$ "xyz" contains echobool cr</lang>
```
Output:
```true
false
true
false
true
false
```

Racket

<lang racket>

1. lang racket

(require srfi/13) (string-prefix? "ab" "abcd") (string-suffix? "cd" "abcd") (string-contains "abab" "bb") (string-contains "abab" "ba") </lang>

Output:
```#t
#t
#f
1
```

Raku

(formerly Perl 6)

Using string methods:

<lang perl6>\$haystack.starts-with(\$needle) # True if \$haystack starts with \$needle \$haystack.contains(\$needle) # True if \$haystack contains \$needle \$haystack.ends-with(\$needle) # True if \$haystack ends with \$needle</lang>

Using regexes:

<lang perl6>so \$haystack ~~ /^ \$needle / # True if \$haystack starts with \$needle so \$haystack ~~ / \$needle / # True if \$haystack contains \$needle so \$haystack ~~ / \$needle \$/ # True if \$haystack ends with \$needle</lang>

Using `substr`:

<lang perl6>substr(\$haystack, 0, \$needle.chars) eq \$needle # True if \$haystack starts with \$needle substr(\$haystack, *-\$needle.chars) eq \$needle # True if \$haystack ends with \$needle</lang>

<lang perl6>\$haystack.match(\$needle, :g)».from; # List of all positions where \$needle appears in \$haystack \$haystack.indices(\$needle :overlap); # Also find any overlapping instances of \$needle in \$haystack</lang>

Retro

<lang Retro>: startsWith? ( \$1 \$2 - f )

``` withLength &swap dip 0 swap ^strings'getSubset compare ;
```

"abcdefghijkl" "abcde" startsWith? "abcdefghijkl" "bcd" startsWith?

"abcdefghijkl" "bcd" ^strings'search "abcdefghijkl" "zmq" ^strings'search

endsWith? ( \$1 \$2 - f )
``` swap withLength + over getLength - compare ;
```

"abcdefghijkl" "ijkl" endsWith? "abcdefghijkl" "abc" endsWith?</lang>

REXX

Extra coding was added to take care of using plurals in the last output message. <lang rexx>/*REXX program demonstrates some basic character string testing (for matching). */ parse arg A B /*obtain A and B from the command line.*/ say 'string A = ' A /*display string A to the terminal.*/ say 'string B = ' B /* " " B " " " */ say copies('░', 70) /*display a line separator (fence). */ LB= length(B) /*get the length of string B in bytes*/ if left(A, LB)==B then say 'string A starts with string B'

```                  else say  "string  A  doesn't start with string  B"
```

say /* [↓] another method using COMPARE BIF*/ p= pos(B, A) if p==0 then say "string A doesn't contain string B"

```        else say  'string  A  contains string  B  (starting in position'   p")"
```

say if right(A, LB)==B then say 'string A ends with string B'

```                   else say "string  A  doesn't end with string  B"
```

say \$=; p= 0; do until p==0; p= pos(B, A, p+1)

```                                 if p\==0  then \$= \$','   p
end   /*until*/
```

\$= space( strip(\$, 'L', ",") ) /*elide extra blanks and leading comma.*/

1. = words(\$) /*obtain number of words in \$ string.*/

if #==0 then say "string A doesn't contain string B"

```        else say 'string  A  contains string  B '    #    " time"left('s', #>1),
"(at position"left('s', #>1)  \$")" /*stick a fork in it,  we're all done. */</lang>
```
output   when the following is specified (the five Marx brothers):   Chico_Harpo_Groucho_Zeppo_Gummo p
```string  A  =  Chico_Harpo_Groucho_Zeppo_Gummo
string  B  =  p
░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

string  A  contains string  B  (starting in position 10)

string  A  doesn't end with string B

string  A  contains string  B  3  times (at positions 10, 23, 24)
```
output   when the following is specified:   Chico_Harpo_Groucho_Zeppo_Gummo Z
```string  A  =  Chico_Harpo_Groucho_Zeppo_Gummo
string  B  =  Z
░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

string  A  contains string  B  (starting in position 21)

string  A  doesn't end with string  B

string  A  contains string  B  1  time (at position 21)
```
output   when the following is specified:   Chico_Harpo_Groucho_Zeppo_Gummo Chi
```string  A  =  Chico_Harpo_Groucho_Zeppo_Gummo
string  B  =  Chi
░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
string  A  starts with string  B

string  A  contains string B  (starting in position 1)

string  A  doesn't end with string  B

string  A  contains string  B  1  time (at position 1)
```
output   when the following is specified:   Chico_Harpo_Groucho_Zeppo_Gummo mmo
```string  A  =  Chico_Harpo_Groucho_Zeppo_Gummo
string  B  =  mmo
░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

string  A  contains string  B  (starting in position 29)

string  A  ends with string  B

string  A  contains string  B  1  time (at position 29)
```

Ring

<lang ring> aString = "Welcome to the Ring Programming Language" bString = "Ring" bStringIndex = substr(aString,bString) if bStringIndex > 0 see "" + bStringIndex + " : " + bString ok </lang>

Ruby

<lang ruby>p 'abcd'.start_with?('ab') #returns true p 'abcd'.end_with?('ab') #returns false p 'abab'.include?('bb') #returns false p 'abab'.include?('ab') #returns true p 'abab'['bb'] #returns nil p 'abab'['ab'] #returns "ab" p 'abab'.index('bb') #returns nil p 'abab'.index('ab') #returns 0 p 'abab'.index('ab', 1) #returns 2 p 'abab'.rindex('ab') #returns 2</lang>

Run BASIC

<lang runbasic>s1\$ = "abc def ghi klmnop" s2\$ = "abc" ' begins with s3\$ = "ef" ' is in the string s4\$ = "nop" ' ends with

sn2\$ = "abcx" ' not begins with sn3\$ = "efx" ' not in the string sn4\$ = "nopx" ' not ends with

if left\$(s1\$,len(s2\$)) <> s2\$ then a\$ = "Not " print "String:";s1\$;" does ";a\$;"begin with:";s2\$

if instr(s1\$,s3\$) = 0 then a\$ = "Not " print "String:";s1\$;" does ";a\$;"contain:";s3\$

if mid\$(s1\$,len(s1\$) + 1 - len(s4\$),len(s4\$)) <> s4\$ then a\$ = "Not " print "String:";s1\$;" does ";a\$;"end with:";s4\$

' ----------- not ----------------------------- print if left\$(s1\$,len(sn2\$)) <> sn2\$ then a\$ = "Not " print "String:";s1\$;" does ";a\$;"begin with:";sn2\$

if instr(s1\$,sn3\$) = 0 then a\$ = "Not " print "String:";s1\$;" does ";a\$;"contain:";sn3\$

if mid\$(s1\$,len(s1\$) + 1 - len(sn4\$),len(sn4\$)) <> sn4\$ then a\$ = "Not " print "String:";s1\$;" does ";a\$;"end with:";sn4\$</lang>

Output:
```String:abc def ghi klmnop does begin with:abc
String:abc def ghi klmnop does contain:ef
String:abc def ghi klmnop does end with:nop

String:abc def ghi klmnop does Not begin with:abcx
String:abc def ghi klmnop does Not contain:efx
String:abc def ghi klmnop does Not end with:nopx```

Rust

<lang rust>fn print_match(possible_match: Option<usize>) {

```   match possible_match {
Some(match_pos) => println!("Found match at pos {}", match_pos),
None => println!("Did not find any matches")
}
```

}

fn main() {

```   let s1 = "abcd";
let s2 = "abab";
let s3 = "ab";

// Determining if the first string starts with second string
assert!(s1.starts_with(s3));
// Determining if the first string contains the second string at any location
assert!(s1.contains(s3));
// Print the location of the match
print_match(s1.find(s3)); // Found match at pos 0
print_match(s1.find(s2)); // Did not find any matches
// Determining if the first string ends with the second string
assert!(s2.ends_with(s3));
```

}</lang>

<lang rust> fn main(){

```   let hello = String::from("Hello world");
println!(" Start with \"he\" {} \n Ends with \"rd\" {}\n Contains \"wi\" {}",
hello.starts_with("He"),
hello.ends_with("ld"),
hello.contains("wi"));
```

}</lang>

Output:
```Start with "he" true
Ends with "ld" true
Contains "wi" false
```

Scala

<lang scala>"abcd".startsWith("ab") //returns true "abcd".endsWith("zn") //returns false "abab".contains("bb") //returns false "abab".contains("ab") //returns true

var loc="abab".indexOf("bb") //returns -1 loc = "abab".indexOf("ab") //returns 0 loc = "abab".indexOf("ab", loc+1) //returns 2</lang>

Seed7

<lang seed7>\$ include "seed7_05.s7i";

const proc: main is func

``` local
var integer: position is 0;
begin
writeln(startsWith("abcd", "ab")); # write TRUE
writeln(endsWith("abcd", "zn"));   # write FALSE
writeln(pos("abab", "bb") <> 0);   # write FALSE
writeln(pos("abab", "ab") <> 0);   # write TRUE
writeln(pos("abab", "bb"));        # write 0
position := pos("abab", "ab");
writeln(position);                 # position is 1
position := pos("abab", "ab", succ(position));
writeln(position);                 # position is 3
end func;</lang>
```
Output:
```TRUE
FALSE
FALSE
TRUE
0
1
3
```

Sidef

<lang ruby>var first = "abc-abcdef-abcd"; var second = "abc";

say first.begins_with(second); #=> true say first.contains(second); #=> true say first.ends_with(second); #=> false

1. Get and print the location of the match

say first.index(second); #=> 0

1. Find multiple occurrences of a string

var pos = -1; while (pos = first.index(second, pos+1) != -1) {

```   say "Match at pos: #{pos}";
```

}</lang>

Smalltalk

<lang smalltalk>a startsWith: b a includesSubCollection: b. "inherited from superclass" a includesString: b. "the same, but more readable" a endsWith: b a indexOfSubCollection: b "inherited" a indexOfSubCollection: b startingAt: pos "inherited" a indexOfString: b a indexOfStringStartingAt: b </lang>

SNOBOL4

<lang SNOBOL4> s1 = 'abcdabefgab'

```     s2 = 'ab'
s3 = 'xy'
OUTPUT = ?(s1 ? POS(0) s2)  "1. " s2 " begins " s1
OUTPUT = ?(s1 ? POS(0) s3)  "1. " s3 " begins " s1  ;# fails
```
```     n = 0
```

again s1 POS(n) ARB s2 @a :F(p3)

```     OUTPUT = "2. " s2 " found at position "
```

+ a - SIZE(s2) " in " s1

```     n = a                                      :(again)
```

p3 OUTPUT = ?(s1 ? s2 RPOS(0)) "3. " s2 " ends " s1 END</lang>

Output:
```1. ab begins abcdabefgab
2. ab found at position 0 in abcdabefgab
2. ab found at position 4 in abcdabefgab
2. ab found at position 9 in abcdabefgab
3. ab ends abcdabefgab```

Standard ML

<lang sml>String.isPrefix "ab" "abcd"; (* returns true *) String.isSuffix "zn" "abcd"; (* returns false *) String.isSubstring "bb" "abab"; (* returns false *) String.isSubstring "ab" "abab"; (* returns true *)

1. 2 (Substring.base (#2 (Substring.position "bb" (Substring.full "abab")))); (* returns 4 *)

val loc = #2 (Substring.base (#2 (Substring.position "ab" (Substring.full "abab")))); (* returns 0 *) val loc' = #2 (Substring.base (#2 (Substring.position "ab" (Substring.extract ("abab", loc+1, NONE))))); (* returns 2 *)</lang>

Swift

<lang swift>var str = "Hello, playground" str.hasPrefix("Hell") //True str.hasPrefix("hell") //False

str.containsString("llo") //True str.containsString("xxoo") //False

str.hasSuffix("playground") //True str.hasSuffix("world") //False</lang>

Tailspin

This assumes the string to be found does not contain any regex special characters, otherwise we should work with composers (parsers) see below. <lang tailspin> templates find&{s:}

``` when <'\$s;.*'> do '\$; starts with \$s;' !
when <'.*\$s;'> do '\$; ends with \$s;' !
when <'.*\$s;.*'> do '\$; contains \$s;' !
otherwise '\$s; cannot be found in \$;' !
```

end find

'abcd' -> find&{s:'ab'} -> !OUT::write ' ' -> !OUT::write 'abcd' -> find&{s:'cd'} -> !OUT::write ' ' -> !OUT::write 'abcd' -> find&{s:'bc'} -> !OUT::write ' ' -> !OUT::write 'abcd' -> find&{s:'e'} -> !OUT::write </lang>

Output:
```abcd starts with ab
abcd ends with cd
abcd contains bc
e cannot be found in abcd
```

Working with composers and literal matchers to be able to handle any string. <lang tailspin> composer startsWith&{s:}

``` @: 0;
(<='\$s;'>? -> @:1; <'.*'>) \$@
```

end startsWith

composer endsWith&{s:}

``` @: 0;
(<ends|'.*'>) \$@
rule ends: (<'.'>* <='\$s;'> -> @:1;)
```

end endsWith

composer contains&{s:}

``` @: 0;
(<~='\$s;'>? <='\$s;'>? -> @:1; <'.*'>) \$@
```

end contains

templates find&{s:}

``` when <?(\$ -> startsWith&{s:\$s} <=1>)> do '\$; starts with \$s;' !
when <?(\$ -> endsWith&{s:\$s} <=1>)> do '\$; ends with \$s;' !
when <?(\$ -> contains&{s:\$s} <=1>)> do '\$; contains \$s;' !
otherwise '\$s; cannot be found in \$;' !
```

end find

'abcd' -> find&{s:'ab'} -> !OUT::write ' ' -> !OUT::write 'abcd' -> find&{s:'cd'} -> !OUT::write ' ' -> !OUT::write 'abcd' -> find&{s:'bc'} -> !OUT::write ' ' -> !OUT::write 'abcd' -> find&{s:'e'} -> !OUT::write ' ' -> !OUT::write 'banana' -> find&{s:'na'} -> !OUT::write </lang>

Output:
```abcd starts with ab
abcd ends with cd
abcd contains bc
e cannot be found in abcd
banana ends with na
```

In tailspin we don't manipulate strings by character indices but we can still work out the second part. String characters can be streamed and captured in an array, although we prefer to compare in strings, here with a composer (parser). This has also been crafted to work with strings containing special regex characters by using literal equality. <lang tailspin> composer index&{s:}

``` @index: 0;
[<match>*]
rule match: ([<~='\$s;'>? ...] -> @: \$@ + 1 + \$::length;) <'.'>? -> \$@
```

end index

'ba is found in positions \$:'banana' -> index&{s:'ba'}; in banana' -> !OUT::write ' ' -> !OUT::write 'ana is found in positions \$:'banana' -> index&{s:'ana'}; in banana' -> !OUT::write ' ' -> !OUT::write 'c is found in positions \$:'banana' -> index&{s:'c'}; in banana' -> !OUT::write </lang>

Output:
```ba is found in positions [1] in banana
ana is found in positions [2, 4] in banana
c is found in positions [] in banana
```

Tcl

In this code, we are looking in various ways for the string in the variable needle in the string in the variable haystack. <lang tcl>set isPrefix [string equal -length [string length \$needle] \$haystack \$needle] set isContained [expr {[string first \$needle \$haystack] >= 0}] set isSuffix [string equal \$needle [string range \$haystack end-[expr {[string length \$needle]-1}] end]]</lang>

Of course, in the cases where the needle is a glob-safe string (i.e., doesn't have any of the characters “*?[\” in), this can be written far more conveniently: <lang tcl>set isPrefix [string match \$needle* \$haystack] set isContained [string match *\$needle* \$haystack] set isSuffix [string match *\$needle \$haystack]</lang>

Another powerful technique is to use the regular expression engine in literal string mode: <lang tcl>set isContained [regexp ***=\$needle \$haystack]</lang> This can be extended by getting the `regexp` to return the locations of the matches, enabling the other forms of match to be done: <lang tcl>set matchLocations [regexp -indices -all -inline ***=\$needle \$haystack]

1. Each match location is a pair, being the index into the string where the needle started
2. to match and the index where the needle finished matching

set isContained [expr {[llength \$matchLocations] > 0}] set isPrefix [expr {[lindex \$matchLocations 0 0] == 0}] set isSuffix [expr {[lindex \$matchLocations end 1] == [string length \$haystack]-1}] set firstMatchStart [lindex \$matchLocations 0 0] puts "Found \"\$needle\" in \"\$haystack\" at \$firstMatchStart" foreach location \$matchLocations {

```   puts "needle matched at index [lindex \$location 0]"
```

}</lang>

TUSCRIPT

IF (string1.sw.string2) THEN PRINT string1," starts with ",string2 ELSE PRINT string1," not starts with ",string2 ENDIF SET beg=STRING (string1,string2,0,0,0,end) IF (beg!=0) THEN PRINT string1," contains ",string2 PRINT " starting in position ",beg PRINT " ending in position ",end ELSE PRINT string1," not contains ",string2 ENDIF

IF (string1.ew.string2) THEN PRINT string1," ends with ",string2 ELSE PRINT string1," not ends with ",string2 ENDIF </lang>

Output:
```string1 >Rosetta Code
string2 >Code
Rosetta Code not starts with Code
Rosetta Code contains        Code
starting in position 9
ending   in position 13
Rosetta Code ends with       Code
```

TXR

TXR Lisp

<lang txrlisp>(tree-case *args*

``` ((big small)
(cond
((< (length big) (length small))
(put-line `@big is shorter than @small`))
((str= big small)
(put-line `@big and @small are equal`))
((starts-with small big)
(put-line `@small is a prefix of @big`))
((ends-with small big)
(put-line `@small is a suffix of @big`))
(t (iflet ((pos (search-str big small)))
(put-line `@small occurs in @big at position @pos`)
(put-line `@small does not occur in @big`)))))
(otherwise
(put-line `usage: @(ldiff *full-args* *args*) <bigstring> <smallstring>`)))</lang>
```
Output:
```\$ txr cmatch2.tl x
usage: txr cmatch2.tl <bigstring> <smallstring>
\$ txr cmatch2.tl x y z
usage: txr cmatch2.tl <bigstring> <smallstring>
\$ txr cmatch2.tl catalog cat
cat is a prefix of catalog
\$ txr cmatch2.tl catalog log
log is a suffix of catalog
\$ txr cmatch2.tl catalog at
at occurs in catalog at position 1
\$ txr cmatch2.tl catalog catalogue
catalog is shorter than catalogue
\$ txr cmatch2.tl catalog catalog
catalog and catalog are equal
\$ txr cmatch2.tl catalog dog
dog does not occur in catalog```

Pattern Language

<lang txr>@line @(cases) @ line @ (output) second line is the same as first line @ (end) @(or) @ (skip)@line @ (output) first line is a suffix of the second line @ (end) @(or) @ line@(skip) @ (output) first line is a suffix of the second line @ (end) @(or) @ prefix@line@(skip) @ (output) first line is embedded in the second line at position @(length prefix) @ (end) @(or) @ (output) first line is not found in the second line @ (end) @(end)</lang>

Output:
```\$ txr cmatch.txr -
123
01234
first line is embedded in the second line at position 1
\$ txr cmatch.txr -
123
0123
first line is a suffix of the second line```

Vala

<lang vala>void main() {

```   var text = "一二三四五六七八九十";
var starts = "一二";
var ends = "九十";
var contains = "五六";
var not_contain = "百";

stdout.printf(@"text: \$text\n\n", );
stdout.printf(@"starts with \$starts: \$(text.has_prefix(starts))\n");
stdout.printf(@"ends with \$ends: \$(text.has_suffix(ends))\n");
stdout.printf(@"starts with \$starts: \$(text.has_suffix(starts))\n");
stdout.printf(@"contains \$contains: \$(contains in text)\n");
stdout.printf(@"contains \$not_contain: \$(contains in text)\n");
```

}</lang>

Output:
```text: 一二三四五六七八九十

starts with 一二: true
ends with 九十: true
starts with 一二: false
contains 五六: true
contains 百: false
```

VBA

Translation of: Phix
<lang vb>Public Sub string_matching()
```   word = "the"                                        '-- (also try this with "th"/"he")
sentence = "the last thing the man said was the"
'--       sentence = "thelastthingthemansaidwasthe" '-- (practically the same results)

'-- A common, but potentially inefficient idiom for checking for a substring at the start is:
If InStr(1, sentence, word) = 1 Then
Debug.Print "yes(1)"
End If
'-- A more efficient method is to test the appropriate slice
If Len(sentence) >= Len(word) _
And Mid(sentence, 1, Len(word)) = word Then
Debug.Print "yes(2)"
End If
'-- Which is almost identical to checking for a word at the end
If Len(sentence) >= Len(word) _
And Mid(sentence, Len(sentence) - Len(word) + 1, Len(word)) = word Then
Debug.Print "yes(3)"
End If
'-- Or sometimes you will see this, a tiny bit more efficient:
If Len(sentence) >= Len(word) _
And InStr(Len(sentence) - Len(word) + 1, sentence, word) Then
Debug.Print "yes(4)"
End If
'-- Finding all occurences is a snap:
r = InStr(1, sentence, word)
Do While r <> 0
Debug.Print r
r = InStr(r + 1, sentence, word)
Loop
```
End Sub</lang>
Output:
```yes(1)
yes(2)
yes(3)
yes(4)
1
16
33 ```

VBScript

<lang vb>Function StartsWith(s1,s2) StartsWith = False If Left(s1,Len(s2)) = s2 Then StartsWith = True End If End Function

Function Contains(s1,s2) Contains = False If InStr(1,s1,s2) Then Contains = True & " at positions " j = 1 Do Until InStr(j,s1,s2) = False Contains = Contains & InStr(j,s1,s2) & ", " If j = 1 Then If Len(s2) = 1 Then j = j + InStr(j,s1,s2) Else j = j + (InStr(j,s1,s2) + (Len(s2) - 1)) End If Else If Len(s2) = 1 Then j = j + ((InStr(j,s1,s2) - j) + 1) Else j = j + ((InStr(j,s1,s2) - j) + (Len(s2) - 1)) End If End If Loop End If End Function

Function EndsWith(s1,s2) EndsWith = False If Right(s1,Len(s2)) = s2 Then EndsWith = True End If End Function

WScript.StdOut.Write "Starts with test, 'foo' in 'foobar': " & StartsWith("foobar","foo") WScript.StdOut.WriteLine WScript.StdOut.Write "Contains test, 'o' in 'fooooobar': " & Contains("fooooobar","o") WScript.StdOut.WriteLine WScript.StdOut.Write "Ends with test, 'bar' in 'foobar': " & EndsWith("foobar","bar")</lang>

Output:
```
Starts with test, 'foo' in 'foobar': True
Contains test, 'o' in 'fooooobar': True at positions 2, 3, 4, 5, 6,
Ends with test, 'bar' in 'foobar': True
```

Visual Basic

Works with: Visual Basic version VB6 Standard

works the same as in VBA, see String_matching#VBA

Wren

<lang ecmascript>var s = "abracadabra" var t = "abra" var u = "ra" var v = "cad" System.print("'%(s)' starts with '%(t)' is %(s.startsWith(t))") var indices = [] var start = 0 while (true) {

```   var ix = s.indexOf(u, start)
if (ix >= 0) {
start = ix + u.count
if (start >= s.count) break
} else break
```

} var contained = indices.count > 0 System.print("'%(s)' contains '%(u)' is %(contained) %(contained ? "at indices %(indices)" : "")") System.print("'%(s)' ends with '%(v)' is %(s.endsWith(v))")</lang>

Output:
```'abracadabra' starts with 'abra' is true
'abracadabra' contains 'ra' is true at indices [2, 9]
```

XPL0

<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations string 0; \use zero-terminated strings

func StrLen(A); \Return number of characters in a string char A; int I; for I:= 0 to -1>>1-1 do

```   if A(I) = 0 then return I;
```

func StrFind(A, B); \Search for string B in string A \Returns index of first occurrence of string B in A, or -1 if B is not found char A, B; \strings to be compared int LA, LB, I, J; [LA:= StrLen(A);

```LB:= StrLen(B);
for I:= 0 to LA-LB do
[for J:= 0 to LB-1 do
if B(J) # A(J+I) then J:= LB+1;
if J = LB then return I;    \found
];
```

return -1; ];

char Str; int I, J; [Str:= "pack my box with"; \ 0123456789012345 Text(0, if StrFind(Str, "pack") = 0 then "yes" else "no"); CrLf(0); \1. Text(0, if StrFind(Str, "ack") = 0 then "yes" else "no"); CrLf(0); I:= StrFind(Str, "x w"); Text(0, if I >= 0 then "yes" else "no"); \2. Text(0, ", at offset "); IntOut(0, I); CrLf(0); I:= 0; J:= 0; \offsets of space characters loop [I:= StrFind(Str+J, " ");

```       if I < 0 then quit;
IntOut(0, I+J); ChOut(0, ^ );
J:= J+I+1;
];
```

CrLf(0); Text(0, if StrFind(Str, "X w") >= 0 then "yes" else "no"); CrLf(0); Text(0, if StrFind(Str, "with") = StrLen(Str)-StrLen("with") then "yes" else "no"); CrLf(0); \3. Text(0, if StrFind(Str, "x w" ) = StrLen(Str)-StrLen("x w" ) then "yes" else "no"); CrLf(0); ]</lang>

Output:
```yes
no
yes, at offset 10
4 7 11
no
yes
no
```

XProfan

<lang XProfan> // XProfan can use StringParts, so the results here // are the comma separated positions of the parts or 0 Proc Contains

```  Parameters string content, part
var string results = "0"
var long posi = 1
posi = InStr(part,content,posi)
if posi <> 0
results = str\$(posi)
repeat
posi = InStr(part,content,posi+1)
case posi <> 0 : results = results + "," + str\$(posi)
until posi == 0
endif
Return results
```

EndProc

Proc StartsWith

```  Parameters string content, part
Return if(Left\$(content,Len(part)) == part, 1, 0)
```

EndProc

Proc EndsWith

```  Parameters string content, part
Return if(Right\$(content,Len(part)) == part, 1, 0)
'Return if(Left\$(content,Len(content)-Len(part)+1) == part, 1, 0)
```

EndProc

var string theContent = "foobar" var string thePart = "foo" Print "Starts with: " Print " ("+thePart+" in "+theContent+") "+if(StartsWith(theContent,thePart),"Yes","No") thePart = "back" Print " ("+thePart+" in "+theContent+") "+if(StartsWith(theContent,thePart),"Yes","No")

theContent = "foooooobar" Print "Contains: " Print " ("+thePart+" in "+theContent+") "+ Contains(theContent,thePart) thePart = "o" Print " ("+thePart+" in "+theContent+") "+ Contains(theContent,thePart)

theContent = "foobar" thePart = "back" Print "Ends with: " Print " ("+thePart+" in "+theContent+") "+if(EndsWith(theContent,thePart),"Yes","No") thePart = "bar" Print " ("+thePart+" in "+theContent+") "+if(EndsWith(theContent,thePart),"Yes","No")

waitkey end</lang>

Output:
```Starts with:
(foo in foobar) Yes
(back in foobar) No
Contains:
(back in foooooobar) 0
(o in foooooobar) 2,3,4,5,6,7
Ends with:
(back in foobar) No
(bar in foobar) Yes
```

Yabasic

```   print "'", cadena1\$, "' comienza con '", cadena2\$, "'"
```

else

```   print "'", cadena1\$, "' no comienza con '", cadena2\$, "'"
```

end if

//Determinar si la primera cadena contiene la segunda cadena en cualquier //ubicación imprima la ubicación de la coincidencia para la parte 2 cadena2\$ = "wert" posic = instr(cadena1\$, cadena2\$) if posic then

```   print "'", cadena1\$, "' contiene '", cadena2\$, "' en la posicion ", posic
```

else

```   print "'", cadena1\$, "' no contiene '", cadena2\$, "'"
```

end if

```   print "'", cadena1\$, "' termina con '", cadena2\$, "'"
```

else

```   print "'", cadena1\$, "' no termina con '", cadena2\$, "'"
```

end if end </lang>

Output:
```'qwertyuiop' comienza con 'qwerty'
'qwertyuiop' contiene 'wert' en la posicion 2
'qwertyuiop' no termina con 'random garbage'
```

zkl

<lang zkl>fcn f(text,p){ if(text.find(p)==0)println("Yep") else println("Nope") } f("foobar","foo") //--> Yep f("foobar","bar") //--> Nope</lang> <lang zkl>fcn f(text,p){ if(Void!=(n:=text.find(p)))println("Contained @",n) else println("Nope") } f("foobar","ob") //--> Contained @2 f("foobar","food") //--> Nope</lang> <lang zkl>fcn f(text,p){

```  if( Void!=(n:=text.rfind(p)) and n+p.len()==text.len() )
println("tail gunner") else println("Nope")
```

} f("foobar","r"); f("foobar","ar"); //--> tail gunners f("foobar","ob"); //--> Nope f("foobarfoobar","bar"); //--> tail gunner</lang>